The hotel industry as one of the three pillars of the tourism industry , the upcoming May Day holiday is bound to reach a peak passenger flow. So , whether it is a business hotel, Inn or a luxury hotel also , before the advent of the peak are doing the appropriate preparations. A rare opportunity , brutal competition , how to stand out in many hotels , win more customers become the hotel industry are thinking about the problem.
We know that to go away on business or pleasure , a basic requirement for the hotel is clean and tidy ,Fixed Length plastic seal the other is quiet. After all, the hotel 's main function is to provide travelers a comfortable seating space walkers , but not all around the hotel is so pleasant and comfortable environment , a variety of factors have led to the hotel's location is not the same , some hotels around the noisy bustle , closed the window also to no avail , the corridor up to and fro footsteps , talking clearly hear the sound of the room so that guests sleep well , also affect the reputation of the hotel . Therefore, many hoteliers will first sights soundproofing industry , the use of sound and reasonable measures to compensate for the noise nuisance caused .
Among them, the installation of doors and windows sealed is the most economical solution ! Our company specializes in producing seals Great variety of standard models of windows and doors seal, door seal , with a D -type , P -, E- , I -type , according to the doors and windows of the main colors are gray, black, white , brown four kinds , can Depending on the size of the gap is to choose a different size, it is mainly made of EPDM imported raw materials, environmental protection, dust-proof , crash , noise effect is very good !
Importantly, seal doors and windows not only cheap , and easy to install, all with a strong adhesive back , as long as the edge of the door or window frame and sash windows in contact with wipe clean after the adhesive glue to tear . It has high elasticity , the doors and windows closed when it will squeeze live closely, there will not be a little gap stainless steel cable ties , play good sound , crash effects , naturally give customers a comfortable , quiet environment to rest .
pull tight security seals
pull tight security seals
2013年12月23日星期一
How to maintain a seal with spring cleaning compartments
Went to the spring, the flowers of the season , after a winter break , a car friends at the same time enjoy the warmth of spring , you might want hikers to travel and enjoy the beauty of nature pull tight straps; You may be busy working day , shuttling between the bustling markets and offices .... but anyway , you do not forget to care about your car , it cheer , good for you.
Spring car, the first is to do body sealing . This is because the spring sand dust weather cause more to deal with such bad weather , the owner ahead of the best window sealing tape carefully check whether there is aging, degumming, cracking , if necessary, replace the sealing strip about aging , enhanced interior seal to prevent sand entering . Such treatment is not only able to deal with dust weather , when the weather gets hot , but also help to strengthen the effect of air conditioning .
Owners need to be reminded that, should try to use the air conditioning outer loop mode, to avoid a lot of dust into the car. Because the spring sandstorm rampant , but after the wind, whether it is the center console , shift lever , seat , floor and so covered with dust, the air inside the car also becomes more turbid, in large sandstorm season, the compartment is also often deposited a layer of dust , and you should pay attention to timely clean. As the car accessories such as door seals ,metal seals etc. are mostly plastic and rubber materials, cleaning must use special cleaning agents and clean soft cloth , not inside and outside the mix ; using professional cleaning agent console , doors and other parts for cleaning and disinfection .
Spring car, the first is to do body sealing . This is because the spring sand dust weather cause more to deal with such bad weather , the owner ahead of the best window sealing tape carefully check whether there is aging, degumming, cracking , if necessary, replace the sealing strip about aging , enhanced interior seal to prevent sand entering . Such treatment is not only able to deal with dust weather , when the weather gets hot , but also help to strengthen the effect of air conditioning .
Owners need to be reminded that, should try to use the air conditioning outer loop mode, to avoid a lot of dust into the car. Because the spring sandstorm rampant , but after the wind, whether it is the center console , shift lever , seat , floor and so covered with dust, the air inside the car also becomes more turbid, in large sandstorm season, the compartment is also often deposited a layer of dust , and you should pay attention to timely clean. As the car accessories such as door seals ,metal seals etc. are mostly plastic and rubber materials, cleaning must use special cleaning agents and clean soft cloth , not inside and outside the mix ; using professional cleaning agent console , doors and other parts for cleaning and disinfection .
2013年12月16日星期一
How to install windows and doors seal ?
Doors and windows sealed into glass sealing tape and tops two kinds. Sealing strip is generally used in the sash , the layering and doors have special sealing strip groove , the main role is through layering and the fan wearing a sealing strip , glass and frame allow fans a closer, thus ensuring the doors and windows air tightness ; installation position sealing tape should be smooth, without curl not stretch , joints should be less than 1mm, sealing strip should match the model , so that the pressure of the pressure over the General Assembly does not go too small will seal strips easy to fall off , glass and fan body is not close , there will be gaps. Sealing tape should use non-toxic, tasteless green special sealing tape .
Installation site on the tops of the doors and windows generally fan, box fan or a seal around the bridge ( wind block ), and enhance the sealing between the frame and the fan . Tops specification is too large or too vertical hair , not only difficult to assemble , and to make windows mobile resistance increases, especially the larger initial resistance turned on and off in place of resistance. Small size , easy-out vertical tank tops high enough , the enable ( gate ) sealing the window is greatly reduced. Tops subject silicide processing, quality tops look for qualified flat surface , bottom plate and vertical hair smooth. No bending , no pitting on the bottom plate . Bubbles. Hair shaft and the bottom plate bonded firmly and evenly coarseness , hair loss is not easy .
With excellent sealing doors and watertight, that noise it? Natural to players ----- soundproof insulating glass . The two or more than two of the glass , with angled aluminum gutter through the column ( which is filled with desiccant ) intervals around the edges of the glass are marked with butyl rubber, polysulfide rubber ; to form a still ,plastic cable ties dry gas, and vacuum performance. Insulating glass with a variety of superior performance insulation, sealing , frost , dust and noise , etc., so many users are more agreeable . Excellent insulating glass which should be clean, free of dust and moisture .
Good production and installation of windows and doors can not be separated , standard production or not of a high standard windows essential. Production equipment and processes determine the overall performance of windows and doors are excellent . As requested, the difference between the diagonal of plastic doors and windows should be controlled in 2 - 3 mm or less , there is a strict process parameters and control, which requires a certain production equipment and technology to do that have excellent quality workforce . So street workshops and regular manufacturers enamel steel doors just one day of difference. One-third of production, seven installation , if not pay attention to the standard installation of doors and windows can cause distortion . Steel thermal coefficient is almost just six times , so be sure to leave joints between window frames and walls, to prevent thermal expansion and contraction , or minor settlement houses ,security stickers windows and doors so deformed . Meanwhile, to ensure waterproofing , thermal insulation, sound insulation , expansion joints must be filled with an elastic material and then sealed with sealing tape . These materials are more expensive , the quality varies greatly , to prevent cutting corners and shoddy installation .
Installation site on the tops of the doors and windows generally fan, box fan or a seal around the bridge ( wind block ), and enhance the sealing between the frame and the fan . Tops specification is too large or too vertical hair , not only difficult to assemble , and to make windows mobile resistance increases, especially the larger initial resistance turned on and off in place of resistance. Small size , easy-out vertical tank tops high enough , the enable ( gate ) sealing the window is greatly reduced. Tops subject silicide processing, quality tops look for qualified flat surface , bottom plate and vertical hair smooth. No bending , no pitting on the bottom plate . Bubbles. Hair shaft and the bottom plate bonded firmly and evenly coarseness , hair loss is not easy .
With excellent sealing doors and watertight, that noise it? Natural to players ----- soundproof insulating glass . The two or more than two of the glass , with angled aluminum gutter through the column ( which is filled with desiccant ) intervals around the edges of the glass are marked with butyl rubber, polysulfide rubber ; to form a still ,plastic cable ties dry gas, and vacuum performance. Insulating glass with a variety of superior performance insulation, sealing , frost , dust and noise , etc., so many users are more agreeable . Excellent insulating glass which should be clean, free of dust and moisture .
Good production and installation of windows and doors can not be separated , standard production or not of a high standard windows essential. Production equipment and processes determine the overall performance of windows and doors are excellent . As requested, the difference between the diagonal of plastic doors and windows should be controlled in 2 - 3 mm or less , there is a strict process parameters and control, which requires a certain production equipment and technology to do that have excellent quality workforce . So street workshops and regular manufacturers enamel steel doors just one day of difference. One-third of production, seven installation , if not pay attention to the standard installation of doors and windows can cause distortion . Steel thermal coefficient is almost just six times , so be sure to leave joints between window frames and walls, to prevent thermal expansion and contraction , or minor settlement houses ,security stickers windows and doors so deformed . Meanwhile, to ensure waterproofing , thermal insulation, sound insulation , expansion joints must be filled with an elastic material and then sealed with sealing tape . These materials are more expensive , the quality varies greatly , to prevent cutting corners and shoddy installation .
Do not let the rain bother me
Summer is the rainy season, recently, has been under a lot of rainfall, which makes me think of the house could not help security. While any major problems, I can not help it, just think if the leaking windows and doors, then perhaps before the rains, our doors and windows sealed can help a little something for everyone to do a small favor.
Continuous rains may give some houses trouble, in order to avoid both inside and outside our houses produce 'tears' phenomenon, we should do some advance preparation measures better.cable seal Before the big rains come, as homeowners check the advance of our best perimeter seal doors and windows are broken and there is the phenomenon of aging. Doors under normal usage, a short time is generally not seal wear and aging phenomena, but if the number of switching windows more frequently, then it is likely to lead to premature aging of the seal or deformed, which may lead to In the case of leaky windows generated when rainy.
The key fact is that the doors and windows sealed, and seal plays an important role in the quality of the doors and windows sealed. Sealing strip windows and doors in steel doors and doors that can be played sealed, waterproof role, in addition to dust, frost, soundproof, warmth, energy-saving effect, so seal doors and windows must have a strong tensile strength, good flexibility, you also need good temperature resistance and resistance to aging. Doors and windows to choose a suitable seal is also extremely important.
Before the advent of persistent rain, we homeowners should be timely preventive measures,stainless steel wire ties early check the tightness of windows and doors, should problems should be promptly replaced on the sealing strip doors and windows. This is not only safe for housing, but also for our own safety!
Continuous rains may give some houses trouble, in order to avoid both inside and outside our houses produce 'tears' phenomenon, we should do some advance preparation measures better.cable seal Before the big rains come, as homeowners check the advance of our best perimeter seal doors and windows are broken and there is the phenomenon of aging. Doors under normal usage, a short time is generally not seal wear and aging phenomena, but if the number of switching windows more frequently, then it is likely to lead to premature aging of the seal or deformed, which may lead to In the case of leaky windows generated when rainy.
The key fact is that the doors and windows sealed, and seal plays an important role in the quality of the doors and windows sealed. Sealing strip windows and doors in steel doors and doors that can be played sealed, waterproof role, in addition to dust, frost, soundproof, warmth, energy-saving effect, so seal doors and windows must have a strong tensile strength, good flexibility, you also need good temperature resistance and resistance to aging. Doors and windows to choose a suitable seal is also extremely important.
Before the advent of persistent rain, we homeowners should be timely preventive measures,stainless steel wire ties early check the tightness of windows and doors, should problems should be promptly replaced on the sealing strip doors and windows. This is not only safe for housing, but also for our own safety!
2013年12月9日星期一
Wire seals can be filled for inkjet printers
Using compatible cartridges, is to use good quality compatible cartridges , compatible cartridges not to recommend filling , such as print cartridges compatible with rich colors , and use it as the original cartridge .
Compatible inject ink or compatible cartridges, printer due to the same principle , it can be injected into the compatible ink , just different filling methods. First, buy a bottle of compatible ink . When the computer issuing the low ink warning ( in fact, some of the ink cartridge did not run out ) , open the front cover of the printer , press the button on the printer cartridge , the cartridge stops at the loading position, and then remove the ink directly .
Now introduced several cartridges filling method ( first make sure the nozzle is not blocked ) :
1, CANON Cartridge (BC-01, 02,03), with transparent tape stuck airflow holes and inkjet cartridges mouth , put the cartridge ejector with the original ball is pressed into the cartridge , as shown in the refilling needle insert ball hole , slowly inject the ink , after refilling is complete, with the ejector flatten the ball in the hole , put off the transparent tape with a paper towel to clean the spill ink on the machine .
2, CANON Cartridge (BC-20), pad of paper stuck to confirm refilling inkjet mouth hole location , with a wire hook to seal the top of the cartridge flow hole hook straight plug made of plastic , with transparent tape pasted printheads refilling needle inserted into the hole slowly inject the ink flow , after the completion of the original flow refilling the hole made with a plastic plug flow ejector pressed into the hole on the machine can be used cartridge print head cleaning twice into the printer after , then the self-test results are perfect.
3, CANON Cartridge (BC-05, 06), pad of paper on the table , make sure refilling hole location , with transparent tape pasted paper pad good print head with a wire hook to seal the top of the cartridge flow hole straight hook made of plastic stoppers after the needle is inserted airflow refilling the hole slowly injected ink refilling is completed , the original air flow inside the plastic stoppers made with ejector airflow hole to push the machine.
4, CANON cartridges (BCI-3e, 5e, 6), the ink outlet sealed with a wire seal , label and use the top of the cartridge ejector original ball is pressed into the cartridges, ink injected slowly push open after the hole, refilling is completed, the ball pushed by the ejector port to refill the machine .
5, LEXMARK cartridges (12A1980C), the cartridge label facing up remove the tag to determine the three lines, three lines drilled with a drill press and then match their color ink is slowly added ,adjustable length plastic seals after refilling the hole with a wire to seal shut .
6, LEXMARK cartridges (1145,12 A1970, 17G0050), plus pad of paper with transparent tape pasted nozzles , insert the top of the needle with a refill , then slowly inject the ink about 25ML, after refilling is completed, put off nozzles with a pad of paper , ink-jet with a paper towel and gently wipe the mouth , can be loaded into the printer. Note Before using the cartridge to the printer head cleaning 1-2 times and then self-test .
7, HP ink cartridges (1843, NO.20, 29A, 26A), the injector nozzles connected to the bell from the remaining ink extraction , pumping ink cartridges in the process should be put on the syringe next . Will be coming down to add ink syringe , and then align the ink from top to bottom hole pressure bell even turn ink into the cartridge ( Figure 2 ) , after refilling is completed, the syringe gasped a little , until the cartridge does not leak up to reduce box pressure ( keeping the syringe in the primary process , the next cartridge . then part of a paper towel to wipe the ink nozzles on the machine can be used.
8, HP ink cartridges (C6578C / D, C1823A / D), first make sure the ink hole location , with a wire hook to the plastic ink hole Seti out in accordance with and match the color of the ink slowly added to the proposed use of the plastic plugs refilling the ejector port to push the machine .
9, HP ink cartridges (51625A/51649A)bolt seals, the cartridge label facing up remove the tag to determine the three lines, three lines drilled with a drill press , according to their color matching the ink was added slowly , with a seal to seal the refilling hole .
Compatible inject ink or compatible cartridges, printer due to the same principle , it can be injected into the compatible ink , just different filling methods. First, buy a bottle of compatible ink . When the computer issuing the low ink warning ( in fact, some of the ink cartridge did not run out ) , open the front cover of the printer , press the button on the printer cartridge , the cartridge stops at the loading position, and then remove the ink directly .
Now introduced several cartridges filling method ( first make sure the nozzle is not blocked ) :
1, CANON Cartridge (BC-01, 02,03), with transparent tape stuck airflow holes and inkjet cartridges mouth , put the cartridge ejector with the original ball is pressed into the cartridge , as shown in the refilling needle insert ball hole , slowly inject the ink , after refilling is complete, with the ejector flatten the ball in the hole , put off the transparent tape with a paper towel to clean the spill ink on the machine .
2, CANON Cartridge (BC-20), pad of paper stuck to confirm refilling inkjet mouth hole location , with a wire hook to seal the top of the cartridge flow hole hook straight plug made of plastic , with transparent tape pasted printheads refilling needle inserted into the hole slowly inject the ink flow , after the completion of the original flow refilling the hole made with a plastic plug flow ejector pressed into the hole on the machine can be used cartridge print head cleaning twice into the printer after , then the self-test results are perfect.
3, CANON Cartridge (BC-05, 06), pad of paper on the table , make sure refilling hole location , with transparent tape pasted paper pad good print head with a wire hook to seal the top of the cartridge flow hole straight hook made of plastic stoppers after the needle is inserted airflow refilling the hole slowly injected ink refilling is completed , the original air flow inside the plastic stoppers made with ejector airflow hole to push the machine.
4, CANON cartridges (BCI-3e, 5e, 6), the ink outlet sealed with a wire seal , label and use the top of the cartridge ejector original ball is pressed into the cartridges, ink injected slowly push open after the hole, refilling is completed, the ball pushed by the ejector port to refill the machine .
5, LEXMARK cartridges (12A1980C), the cartridge label facing up remove the tag to determine the three lines, three lines drilled with a drill press and then match their color ink is slowly added ,adjustable length plastic seals after refilling the hole with a wire to seal shut .
6, LEXMARK cartridges (1145,12 A1970, 17G0050), plus pad of paper with transparent tape pasted nozzles , insert the top of the needle with a refill , then slowly inject the ink about 25ML, after refilling is completed, put off nozzles with a pad of paper , ink-jet with a paper towel and gently wipe the mouth , can be loaded into the printer. Note Before using the cartridge to the printer head cleaning 1-2 times and then self-test .
7, HP ink cartridges (1843, NO.20, 29A, 26A), the injector nozzles connected to the bell from the remaining ink extraction , pumping ink cartridges in the process should be put on the syringe next . Will be coming down to add ink syringe , and then align the ink from top to bottom hole pressure bell even turn ink into the cartridge ( Figure 2 ) , after refilling is completed, the syringe gasped a little , until the cartridge does not leak up to reduce box pressure ( keeping the syringe in the primary process , the next cartridge . then part of a paper towel to wipe the ink nozzles on the machine can be used.
8, HP ink cartridges (C6578C / D, C1823A / D), first make sure the ink hole location , with a wire hook to the plastic ink hole Seti out in accordance with and match the color of the ink slowly added to the proposed use of the plastic plugs refilling the ejector port to push the machine .
9, HP ink cartridges (51625A/51649A)bolt seals, the cartridge label facing up remove the tag to determine the three lines, three lines drilled with a drill press , according to their color matching the ink was added slowly , with a seal to seal the refilling hole .
2013年12月2日星期一
To help you choose the wire and cable protection cover reasonable
Issues related to the cable model
1, SYV: solid polyethylene insulation RF coaxial cable
2, SYWV (Y): physical foam polyethylene insulation cable systems cable , video ( RF ) coaxial cable (SYV, SYWV, SYFV) applies to closed-circuit TV surveillance and Engineering
SYWV (Y), SYKV cable TV, broadband network dedicated cable structure: ( coax ) oxygen-free round copper single physical polyethylene foam ( insulation ) ( tin wire aluminum ) PVC (PE )
3, the signal control cable (RVV sheathed cable , RVVP shield ) suitable for building intercom , burglar alarm, fire protection, automatic meter reading and other projects
RVVP: copper core PVC insulated shielded PVC sheathed cable core voltage 300V/300V2-24
Purpose : equipment, instruments,security stickers intercom, monitoring, control installation
4, RG: physical foam polyethylene insulation for coaxial cable access network fiber hybrid network (HFC) analog signals transmitted data
5, KVVP: braided shield PVC sheathed cable uses: signal transmission electrical, instrumentation, power distribution unit , control, measurement
6, RVV (227IEC52/53) PVC insulated flexible cable uses: household appliances, small electric tools , instruments and power lighting
7, AVVR PVC sheathed flexible cable installation
8 , junction box SBVV HYA data communication cables ( indoor and outdoor ) for telephone communications and radio equipment connected to telephone wiring network wiring and use
9, RV, RVP PVC insulated cables
10, RVS, RVB for household appliances, small electric tools, instruments, meters, lighting and power connection cable
11, BV, BVR PVC insulated cables use: apply to electrical instrumentation and dynamic lighting for fixed wiring
12, RIB speaker cable ( fever line )
13, KVV PVC insulated control cable uses: electrical, instrumentation, power distribution unit signal transmission, control, measurement
14, SFTP twisted pair telephone,cable ties data and information network
15, UL2464 computer cable
16, VGA monitor cable
17, SYV coaxial cable wireless communications , broadcasting , surveillance systems engineering, and related electronic equipment to transmit RF signals ( including integrated with coaxial cable )
18, SDFAVP, SDFAVVP, SYFPY coaxial cable, elevator
19, JVPV, JVPVP, JVVP core PVC insulated and sheathed copper wire braided computer control cable
1, SYV: solid polyethylene insulation RF coaxial cable
2, SYWV (Y): physical foam polyethylene insulation cable systems cable , video ( RF ) coaxial cable (SYV, SYWV, SYFV) applies to closed-circuit TV surveillance and Engineering
SYWV (Y), SYKV cable TV, broadband network dedicated cable structure: ( coax ) oxygen-free round copper single physical polyethylene foam ( insulation ) ( tin wire aluminum ) PVC (PE )
3, the signal control cable (RVV sheathed cable , RVVP shield ) suitable for building intercom , burglar alarm, fire protection, automatic meter reading and other projects
RVVP: copper core PVC insulated shielded PVC sheathed cable core voltage 300V/300V2-24
Purpose : equipment, instruments,security stickers intercom, monitoring, control installation
4, RG: physical foam polyethylene insulation for coaxial cable access network fiber hybrid network (HFC) analog signals transmitted data
5, KVVP: braided shield PVC sheathed cable uses: signal transmission electrical, instrumentation, power distribution unit , control, measurement
6, RVV (227IEC52/53) PVC insulated flexible cable uses: household appliances, small electric tools , instruments and power lighting
7, AVVR PVC sheathed flexible cable installation
8 , junction box SBVV HYA data communication cables ( indoor and outdoor ) for telephone communications and radio equipment connected to telephone wiring network wiring and use
9, RV, RVP PVC insulated cables
10, RVS, RVB for household appliances, small electric tools, instruments, meters, lighting and power connection cable
11, BV, BVR PVC insulated cables use: apply to electrical instrumentation and dynamic lighting for fixed wiring
12, RIB speaker cable ( fever line )
13, KVV PVC insulated control cable uses: electrical, instrumentation, power distribution unit signal transmission, control, measurement
14, SFTP twisted pair telephone,cable ties data and information network
15, UL2464 computer cable
16, VGA monitor cable
17, SYV coaxial cable wireless communications , broadcasting , surveillance systems engineering, and related electronic equipment to transmit RF signals ( including integrated with coaxial cable )
18, SDFAVP, SDFAVVP, SYFPY coaxial cable, elevator
19, JVPV, JVPVP, JVVP core PVC insulated and sheathed copper wire braided computer control cable
Installation and maintenance of automotive sealing strip
In the cold winter , the owners will notice whether directly immersed in cold car, occasionally accompanied by wind noise , I feel like the door is not closed tightly same. So this time we have to check the seal it. Airtight seal can be improved to prevent rain from entering the inner compartment . Once the seal breakage aging will cause the car leaks , increasing the car's driving wind noise , leaks and very easy to make body rust. It is not difficult to see , the car , the seal is an important part , the usual maintenance checks must periodically . There are now many professional vehicles sealed shop for different models tailored to exactly match the original car curve slope and curvature of the curve , to ensure continuity between the various body parts to avoid flow separation to produce binding sites , easily resolved periodic tail flow , can reduce wind noise at high speeds , while enhancing the original car 's airtight and dustproof capabilities.
Sealed several key positions
Before installing the glass doors of the vehicle to clear the debris carefully notch within such as mortar , brick dust, wood , etc., should be placed carefully on the glass , ensuring that both sides of the gap is uniform and timely than the positive fixed to prevent collisions shift deviate from the slot center. Rubber seal can not pull too tight , cutting length longer than the assembly length 20-30mm. When installing the mosaic in place, flat surfaces , and glass notch in close contact , so that the glass surrounding the force evenly. In the corner of the rubber should be beveled off and disconnect the injection of glue at the firm . When caulk sealant fixed glass , you should use rubber or rubber block glass and choked , leaving voids plastic injection , plastic injection depth should not be less than 5mm, before the glue curing , the glass should be kept free from vibration.
Vehicle frontier sealed trailing edge and side edge seals: support from the hood, on the hood front, rear and along the side edges of the anastomotic site and the body paste , you can void between the hood and the body effectively sealed vehicles on the way, can accelerate the air from the intake gate through improved thermal performance. At the same time , you can reduce the hood and the front part , the friction between the left and right front fender , reducing noise and friction caused by the bump . If the gap is large, you can paste layers.
Four doors and through the gap between the sealing body , the sealing performance of the vehicle can be effectively improved to reduce wind noise . Improve sealing performance can also prevent dust , rainwater into the cockpit to improve the efficiency of air conditioning and refrigeration . Carefully coated with special glue on the inside of the door , will cut a good seal side also coated with special glue, and then the door inside door seal affixed along the circle .
On the roof around the paste , can effectively improve the seal, dustproof and waterproof ; wrapped pipes for air conditioning and refrigeration , can improve the cooling efficiency. Between the door trim panels and the gap between the dashboard , storage boxes and other interior parts of the car , because the assembly and machining accuracy and other reasons, there is often friction , vehicle process will cause resonance at different speeds generate disturbing noise, which is generally very difficult to find . In fact, know the reason, as long as the seal to fill these gaps , paste.
When the door flange seal repair , the repair should be noted that damage to the sealing flange , the flange accurately recover the original shape . After repairing the door seal to conduct inspection , inspection methods are: put a piece of cardboard in a sealed position, close the door , and then pull the paper , according to the Rally to determine the size of the seal is good. If the force required to pull the paper too much explanation sealed tight , it will affect the normal shut the door , and also due to deformation of the seal over the Omo rapid loss of sealing performance ;bolt seals If the force required to pull the paper through the small , indicating poor seals , often have no doors windshield rain phenomenon. When replacing the door must pay attention to the inner and outer door panels in the new bite at the painted folding plastic cuffs and put some holes left when punching with the base tape blocked .
Note that when the sealing repair in several places
In the rear window glass damage , changing the original window glass with the same curvature of the glass , and glass to check the guides and seals for damage. As the windows after repair often reply less than its original shape , therefore , when in addition to ensure easy pulling or lifting the window glass , but also pay attention to the rear window glass in the windows closed around the seal. If the glass with glass notch uneven gaps , rubber and glass tank exposed, protruding notch glass , hand seals can be easily pulled off .
When changing the roof , the roof should be painted in the periphery of the laminated layer of conductive sealant , to be in the water tank and then weld seams and hems over painted plastic, which not only helps the body sealing , more prevents water body due to flange welds produce early rust.
When replacing the entire body , except for the above projects should be completed , but also on their part and weld lap joints are coated with a layer of sealant layer thickness should be about 1mm, and may not have virtual sticky glue , bubbles and other defects ; should be painted in the fold of the hem special glue ; under the entire floor surface should be coated surface and the front cover under the elastomeric coating and anti-corrosion coating of 3mm-4mm ; these measures can not only greatly enhance the whole sealing and corrosion slows the car body speed , but also can greatly enhance comfort.
Routine maintenance required to put in place
The first is to check whether the automotive sealing large cracks , with or without fracture. If the seal broken or larger cracks can be repaired using an adhesive . Particularly the use of special adhesive seal , it is easy to put up a big crack of good . Of course , if the seal of serious injury , or a greater degree of aging , it is best to replace the new seal easy. Replacing the seal is not difficult , but in order to do a better job , better ask professionals .
Sealing strip routine maintenance work , including the following. The first is the use of the car wash detergent , after the cleaning, coated with a high permeability of the protective agent in order to prevent the aging of the seal . In addition , it is easy to fill up the gap between the dust seal , causing corrosion. For this reason , you should use a brush to remove dust and other clean.
Doors and windows sealing strip is an important part of effective measures to ensure that it is airtight doors , watertight , sound , etc., but it is also a reliable guarantee of glass in windows and doors after by external security presence . Since the seal affected by climate and sunlight produces contraction, aging, deformation , and therefore ,colored cable ties the sealing strip is not allowed to work under tension , should remain in the free state . In order to firmly stuck to the glass , the installation process will tend to pull too tight seal , can not guarantee a free state , so that in the tensile deformation state. Practice has proved that , due to the seal installed in tensile deformation state, has emerged seal off, pull off , cracks and other phenomena . For this reason , during installation, the length of the seal assembly of doors side than the more , the slope at the corner is turned off, the adhesive stick firmly , allow sufficient telescoping margin.
Sealed several key positions
Before installing the glass doors of the vehicle to clear the debris carefully notch within such as mortar , brick dust, wood , etc., should be placed carefully on the glass , ensuring that both sides of the gap is uniform and timely than the positive fixed to prevent collisions shift deviate from the slot center. Rubber seal can not pull too tight , cutting length longer than the assembly length 20-30mm. When installing the mosaic in place, flat surfaces , and glass notch in close contact , so that the glass surrounding the force evenly. In the corner of the rubber should be beveled off and disconnect the injection of glue at the firm . When caulk sealant fixed glass , you should use rubber or rubber block glass and choked , leaving voids plastic injection , plastic injection depth should not be less than 5mm, before the glue curing , the glass should be kept free from vibration.
Vehicle frontier sealed trailing edge and side edge seals: support from the hood, on the hood front, rear and along the side edges of the anastomotic site and the body paste , you can void between the hood and the body effectively sealed vehicles on the way, can accelerate the air from the intake gate through improved thermal performance. At the same time , you can reduce the hood and the front part , the friction between the left and right front fender , reducing noise and friction caused by the bump . If the gap is large, you can paste layers.
Four doors and through the gap between the sealing body , the sealing performance of the vehicle can be effectively improved to reduce wind noise . Improve sealing performance can also prevent dust , rainwater into the cockpit to improve the efficiency of air conditioning and refrigeration . Carefully coated with special glue on the inside of the door , will cut a good seal side also coated with special glue, and then the door inside door seal affixed along the circle .
On the roof around the paste , can effectively improve the seal, dustproof and waterproof ; wrapped pipes for air conditioning and refrigeration , can improve the cooling efficiency. Between the door trim panels and the gap between the dashboard , storage boxes and other interior parts of the car , because the assembly and machining accuracy and other reasons, there is often friction , vehicle process will cause resonance at different speeds generate disturbing noise, which is generally very difficult to find . In fact, know the reason, as long as the seal to fill these gaps , paste.
When the door flange seal repair , the repair should be noted that damage to the sealing flange , the flange accurately recover the original shape . After repairing the door seal to conduct inspection , inspection methods are: put a piece of cardboard in a sealed position, close the door , and then pull the paper , according to the Rally to determine the size of the seal is good. If the force required to pull the paper too much explanation sealed tight , it will affect the normal shut the door , and also due to deformation of the seal over the Omo rapid loss of sealing performance ;bolt seals If the force required to pull the paper through the small , indicating poor seals , often have no doors windshield rain phenomenon. When replacing the door must pay attention to the inner and outer door panels in the new bite at the painted folding plastic cuffs and put some holes left when punching with the base tape blocked .
Note that when the sealing repair in several places
In the rear window glass damage , changing the original window glass with the same curvature of the glass , and glass to check the guides and seals for damage. As the windows after repair often reply less than its original shape , therefore , when in addition to ensure easy pulling or lifting the window glass , but also pay attention to the rear window glass in the windows closed around the seal. If the glass with glass notch uneven gaps , rubber and glass tank exposed, protruding notch glass , hand seals can be easily pulled off .
When changing the roof , the roof should be painted in the periphery of the laminated layer of conductive sealant , to be in the water tank and then weld seams and hems over painted plastic, which not only helps the body sealing , more prevents water body due to flange welds produce early rust.
When replacing the entire body , except for the above projects should be completed , but also on their part and weld lap joints are coated with a layer of sealant layer thickness should be about 1mm, and may not have virtual sticky glue , bubbles and other defects ; should be painted in the fold of the hem special glue ; under the entire floor surface should be coated surface and the front cover under the elastomeric coating and anti-corrosion coating of 3mm-4mm ; these measures can not only greatly enhance the whole sealing and corrosion slows the car body speed , but also can greatly enhance comfort.
Routine maintenance required to put in place
The first is to check whether the automotive sealing large cracks , with or without fracture. If the seal broken or larger cracks can be repaired using an adhesive . Particularly the use of special adhesive seal , it is easy to put up a big crack of good . Of course , if the seal of serious injury , or a greater degree of aging , it is best to replace the new seal easy. Replacing the seal is not difficult , but in order to do a better job , better ask professionals .
Sealing strip routine maintenance work , including the following. The first is the use of the car wash detergent , after the cleaning, coated with a high permeability of the protective agent in order to prevent the aging of the seal . In addition , it is easy to fill up the gap between the dust seal , causing corrosion. For this reason , you should use a brush to remove dust and other clean.
Doors and windows sealing strip is an important part of effective measures to ensure that it is airtight doors , watertight , sound , etc., but it is also a reliable guarantee of glass in windows and doors after by external security presence . Since the seal affected by climate and sunlight produces contraction, aging, deformation , and therefore ,colored cable ties the sealing strip is not allowed to work under tension , should remain in the free state . In order to firmly stuck to the glass , the installation process will tend to pull too tight seal , can not guarantee a free state , so that in the tensile deformation state. Practice has proved that , due to the seal installed in tensile deformation state, has emerged seal off, pull off , cracks and other phenomena . For this reason , during installation, the length of the seal assembly of doors side than the more , the slope at the corner is turned off, the adhesive stick firmly , allow sufficient telescoping margin.
2013年11月22日星期五
Dry gas seals used in the centrifuge
Improvement of the mechanical seal
Centrifuge traditional mechanical seals, mechanical seals are the advantages of simple structure, mature technology, machining accuracy is not required; drawback is that life is short, power consumption, there must be a liquid medium to lubricate and cool the sealing surface, the production process parameter fluctuations great seal. Since the operation centrifuges, mechanical seal life has been very short, only five months longest, replace the mechanical seal needs 28h, seriously affecting production. And after the mechanical seal (referred mechanical seal) failure is leaking liquid hexane, hexane is flammable, explosive media, not only the existence of a significant security risk, but also caused serious pollution to the environment. Based on this, we decided to change it to dry gas seal, to enhance economic efficiency and eliminate security risks. Dry gas seal is the most advanced form of a non-contact seal, mainly by the rotating ring, stationary ring, ring, spring, spring seat and sleeve components.
After rotating ring sealing surface grinding and polishing process, and the processed fluid at the dynamic pressure grooves, Figure 2. Dry gas seals rotary ring is rotated, the dynamic pressure of the sealing gas is sucked into the tank, the throttling effect of the sealing weir, into the sealing surface of the gas is compressed under the action of the gas pressure, the sealing surface is open, the gas flow forming a thin gas film between the two sealing surfaces and a thickness of 3 ~ 5um,high security cable seals when the reaction force together with aerostatic air film and the formation of the spring force is equal to the thickness of the air film is very stable, thus ensuring the seal reliability.
We analyze the structure of the centrifuge, decided not to change the device structure, the use of double-end dry gas seal, the same size as the original seal size, and a similar structure, easy to install, see Figure 3. Taking into account the process medium plastic powder, using hexane for cleaning sealed chamber for cleaning. Dynamic pressure dry gas seal ring groove machined end face, using tungsten carbide ring (WC) material, which has a high surface hardness, wear resistance, thermal conductivity coefficient, etc.; static ring using impregnated graphite material, which has high strength, good lubricating properties and high temperature, etc. from.
Seal gas is nitrogen, provided by external network, the maximum pressure is 0.7MPa, the normal operating pressure of 0.5-0.6MPa, the minimum pressure of 0.4MPa, the nitrogen flow is greater than l0 standard m3 / h.
0.7MPa nitrogen is passed through the filtration unit under reduced pressure to 0.5 MPa, into the sealed chamber through a flow meter. To prevent the pipe network in the nitrogen pressure fluctuations for emergency spare bottle with nitrogen gas source, alternate air source can supply 2h. Dry gas seal leakage from the flow meter showed normal operation, the nitrogen leak kept within a stable range,identification cable ties if the leakage continues to increase, the seal chamber pressure will drop, when the pressure drops Bian 0.3MPa, interlock parking to Centrifuge ensure safety. From the actual operation situation, the nitrogen pressure in the 0.5MPa, to ensure the good functioning at this time, nitrogen consumption was 0.48 standard m3 / h, less than the design of a standard m3 / h.
Centrifuge traditional mechanical seals, mechanical seals are the advantages of simple structure, mature technology, machining accuracy is not required; drawback is that life is short, power consumption, there must be a liquid medium to lubricate and cool the sealing surface, the production process parameter fluctuations great seal. Since the operation centrifuges, mechanical seal life has been very short, only five months longest, replace the mechanical seal needs 28h, seriously affecting production. And after the mechanical seal (referred mechanical seal) failure is leaking liquid hexane, hexane is flammable, explosive media, not only the existence of a significant security risk, but also caused serious pollution to the environment. Based on this, we decided to change it to dry gas seal, to enhance economic efficiency and eliminate security risks. Dry gas seal is the most advanced form of a non-contact seal, mainly by the rotating ring, stationary ring, ring, spring, spring seat and sleeve components.
After rotating ring sealing surface grinding and polishing process, and the processed fluid at the dynamic pressure grooves, Figure 2. Dry gas seals rotary ring is rotated, the dynamic pressure of the sealing gas is sucked into the tank, the throttling effect of the sealing weir, into the sealing surface of the gas is compressed under the action of the gas pressure, the sealing surface is open, the gas flow forming a thin gas film between the two sealing surfaces and a thickness of 3 ~ 5um,high security cable seals when the reaction force together with aerostatic air film and the formation of the spring force is equal to the thickness of the air film is very stable, thus ensuring the seal reliability.
We analyze the structure of the centrifuge, decided not to change the device structure, the use of double-end dry gas seal, the same size as the original seal size, and a similar structure, easy to install, see Figure 3. Taking into account the process medium plastic powder, using hexane for cleaning sealed chamber for cleaning. Dynamic pressure dry gas seal ring groove machined end face, using tungsten carbide ring (WC) material, which has a high surface hardness, wear resistance, thermal conductivity coefficient, etc.; static ring using impregnated graphite material, which has high strength, good lubricating properties and high temperature, etc. from.
Seal gas is nitrogen, provided by external network, the maximum pressure is 0.7MPa, the normal operating pressure of 0.5-0.6MPa, the minimum pressure of 0.4MPa, the nitrogen flow is greater than l0 standard m3 / h.
0.7MPa nitrogen is passed through the filtration unit under reduced pressure to 0.5 MPa, into the sealed chamber through a flow meter. To prevent the pipe network in the nitrogen pressure fluctuations for emergency spare bottle with nitrogen gas source, alternate air source can supply 2h. Dry gas seal leakage from the flow meter showed normal operation, the nitrogen leak kept within a stable range,identification cable ties if the leakage continues to increase, the seal chamber pressure will drop, when the pressure drops Bian 0.3MPa, interlock parking to Centrifuge ensure safety. From the actual operation situation, the nitrogen pressure in the 0.5MPa, to ensure the good functioning at this time, nitrogen consumption was 0.48 standard m3 / h, less than the design of a standard m3 / h.
Mechanical seal failure to take measures to deal with
If the mechanical seal parts fails, you need to replace parts or increase machining precision parts, precision mechanical seals to improve the precision and the pump itself, other components of the mechanical seal is very favorable. In order to improve the sealing effect of the movement of the ring and the friction surface finish roughness higher. Width of the friction surface of the ring movement is not, generally between 2 to 7 mm.
Mechanical seal vibration, heat treatment
If the gap between the sealing ring and the movement of the small chamber, the inner diameter of seal chamber should increase or decrease the outer diameter of rotation, a gap of at least 0.75mm guaranteed. If the friction pair is improper, it is necessary to change the static ring material to temperature, corrosion resistance. This will reduce the mechanical vibration and heat sealed.
Handling mechanical seal leakage
Mechanical seal leakage is due to a variety of causes, we have to deal with specific issues. In order to minimize the amount of leakage, must be strictly in accordance with the technical requirements for the installation of mechanical seal assembly, but also pay attention to the following matters.
(1) assembly to be clean and smooth. Mechanical seal parts, tools, lubricants, wiping material to be very clean. Movement ring seal face use a soft gauze wipe. (2) trimming chamfer rounding. Shaft seal cover, such as chamfers to trim and smooth, rounded shaft and cover related to sanding polish. (3) secondary seal assembly, the auxiliary seal rubber gasoline, kerosene can not be soaked and washed to avoid swelling deformation,bolt security seal premature aging. After the static ring assembly, hand pressed compensation loop, checking is in place, is flexible; elastic snap ring is positioned reliable. Ring is installed, you must ensure that it is flexible shaft axial movement.
Shaft channeling large processing
Rational design of axial force balance device, eliminating axial channeling. To meet this requirement, the multi-stage centrifugal pumps, design options are: balance disc plus axial thrust bearing, the balance disc balance the axial force, the axial thrust bearing on the shaft axial limit.
Adding auxiliary flushing system
Seal chamber sealing medium containing particles, impurities must be flushed, because otherwise the precipitated crystals, particles, deposition of impurities, the mechanical seal spring failure, if the particles entering the friction will cause rapid destruction of the mechanical seal. Therefore, secondary mechanical seal flush system is very important, it can effectively protect the sealing surface, played cooling, lubrication, wash away debris and so on.
Pump vibration treatment measures
In the manufacturing assembly process pump products in strict accordance with the standards and procedures to perform, to eliminate vibration source. Pumps, motors, chassis, piping and other auxiliary equipment on site during on-site installation, to strictly eliminate vibration source.
Studied more than simple mechanical seals on rotating equipment applications and emerging fault,metal seals later encountered mechanical seal failure problems, we must first consider the impact factors of mechanical seals itself, and then also consider some factors outside of the mechanical seal. For example: In analyzing the causes of the accident quality mechanical seal, taking into account the impact on other parts of the pump mechanical seal operation, take measures to continuously improve the mechanical seal effect.
Mechanical seal vibration, heat treatment
If the gap between the sealing ring and the movement of the small chamber, the inner diameter of seal chamber should increase or decrease the outer diameter of rotation, a gap of at least 0.75mm guaranteed. If the friction pair is improper, it is necessary to change the static ring material to temperature, corrosion resistance. This will reduce the mechanical vibration and heat sealed.
Handling mechanical seal leakage
Mechanical seal leakage is due to a variety of causes, we have to deal with specific issues. In order to minimize the amount of leakage, must be strictly in accordance with the technical requirements for the installation of mechanical seal assembly, but also pay attention to the following matters.
(1) assembly to be clean and smooth. Mechanical seal parts, tools, lubricants, wiping material to be very clean. Movement ring seal face use a soft gauze wipe. (2) trimming chamfer rounding. Shaft seal cover, such as chamfers to trim and smooth, rounded shaft and cover related to sanding polish. (3) secondary seal assembly, the auxiliary seal rubber gasoline, kerosene can not be soaked and washed to avoid swelling deformation,bolt security seal premature aging. After the static ring assembly, hand pressed compensation loop, checking is in place, is flexible; elastic snap ring is positioned reliable. Ring is installed, you must ensure that it is flexible shaft axial movement.
Shaft channeling large processing
Rational design of axial force balance device, eliminating axial channeling. To meet this requirement, the multi-stage centrifugal pumps, design options are: balance disc plus axial thrust bearing, the balance disc balance the axial force, the axial thrust bearing on the shaft axial limit.
Adding auxiliary flushing system
Seal chamber sealing medium containing particles, impurities must be flushed, because otherwise the precipitated crystals, particles, deposition of impurities, the mechanical seal spring failure, if the particles entering the friction will cause rapid destruction of the mechanical seal. Therefore, secondary mechanical seal flush system is very important, it can effectively protect the sealing surface, played cooling, lubrication, wash away debris and so on.
Pump vibration treatment measures
In the manufacturing assembly process pump products in strict accordance with the standards and procedures to perform, to eliminate vibration source. Pumps, motors, chassis, piping and other auxiliary equipment on site during on-site installation, to strictly eliminate vibration source.
Studied more than simple mechanical seals on rotating equipment applications and emerging fault,metal seals later encountered mechanical seal failure problems, we must first consider the impact factors of mechanical seals itself, and then also consider some factors outside of the mechanical seal. For example: In analyzing the causes of the accident quality mechanical seal, taking into account the impact on other parts of the pump mechanical seal operation, take measures to continuously improve the mechanical seal effect.
2013年11月5日星期二
DME-resistant rubber sealing material standards
From Yunnan Coal Chemical Institute of Applied Technology released the "dimethyl ether rubber sealing material" corporate standard at June 1, 2010 implementation. This is currently the dimethyl ether rubber sealing material products first corporate standards.
Yunnan Institute of Applied Technology in formulating released "dimethyl ether rubber sealing material" corporate standard, the DME-resistant rubber material is divided into A and B categories.plastic truck seals A class suitable for long term or full contact with the case of DME, such as liquefied DME cylinder valve cylinder; B class or parts suitable for intermittent contact with the case of use of dimethyl ether, such as adjusting the valve or valves. Standard proposed product of the technical control indicators, DME-resistant rubber sealing material product quality to provide a detection method and the application of judgment basis.
New DME rubber sealing material and the successful development of "dimethyl ether rubber sealing material" corporate standard release, will be conducive to dimethyl ether product application and promotion.
Currently, DME as a clean fuel has been widely recognized. Since the conventional DME liquefied petroleum gas, diesel and other physical and chemical properties of the fuel there is a big difference in resistance, the sealing material as a constraint DME DME application is an important factor. To this end, Yunnan Academy of play in the rubber research in technology, research and development of new thematic groups established DME-resistant rubber seal materials research through several tests, to obtain better results. self-locking cable ties They have developed resistance to dimethyl ether rubber sealing material by Yunnan Rubber Product Quality Supervision and Inspection Station and the National Gas Appliances Quality Supervision and Inspection Center, the performance indicators meet the sealing material material requirements, especially in the anti-media volume change rate and quality changes rates have a greater breakthrough.
Yunnan Institute of Applied Technology in formulating released "dimethyl ether rubber sealing material" corporate standard, the DME-resistant rubber material is divided into A and B categories.plastic truck seals A class suitable for long term or full contact with the case of DME, such as liquefied DME cylinder valve cylinder; B class or parts suitable for intermittent contact with the case of use of dimethyl ether, such as adjusting the valve or valves. Standard proposed product of the technical control indicators, DME-resistant rubber sealing material product quality to provide a detection method and the application of judgment basis.
New DME rubber sealing material and the successful development of "dimethyl ether rubber sealing material" corporate standard release, will be conducive to dimethyl ether product application and promotion.
Currently, DME as a clean fuel has been widely recognized. Since the conventional DME liquefied petroleum gas, diesel and other physical and chemical properties of the fuel there is a big difference in resistance, the sealing material as a constraint DME DME application is an important factor. To this end, Yunnan Academy of play in the rubber research in technology, research and development of new thematic groups established DME-resistant rubber seal materials research through several tests, to obtain better results. self-locking cable ties They have developed resistance to dimethyl ether rubber sealing material by Yunnan Rubber Product Quality Supervision and Inspection Station and the National Gas Appliances Quality Supervision and Inspection Center, the performance indicators meet the sealing material material requirements, especially in the anti-media volume change rate and quality changes rates have a greater breakthrough.
Mechanical seals are the primary method of modern shaft seal
Modern shaft seal mechanical seal is the main method, though use of it is not easy to achieve completely leak, but the reach of tiny, it is perfectly acceptable amount of leakage is entirely possible. However, the operation of the pump, but often embarrassing situation, then the mechanical seal failure because what is it?
1, the mechanical seal material selection inappropriate. Mechanical seal material and the transmission medium does not match. In operation, the sealing element will soon be corrosion, dissolution or wear, thus losing the sealing capability. Therefore, according to the nature of the transmission medium and the choice of the mechanical seal material is to ensure its sealing function and the normal life of the prerequisites.
2, the mechanical seal flush condition does not meet the design requirements. In conveying easy to crystallize or fine particles of the medium, there must be a certain pressure and a certain flow of fluid to wash, or their crystals or particles will accelerate the sealing wear and affect the sealing of worn automatic compensation leak. Therefore, according to the nature of the transmission medium not only to configure the appropriate flushing lines, but also to install a monitoring and regulation instruments and devices to ensure that fluid pressure and flow to meet the design requirements, in order to maintain the normal operation of the mechanical black cable ties, which is often overlooked by users.
3, each of the mechanical seal can withstand the pressure is limited, due to the seal chamber pressure measurement are not allowed, resulting in the seal chamber pressure exceeds the mechanical seal can withstand the pressure of the leak, is a common sealing One reason for failure.
4, the mechanical seal operating temperature can not exceed the specified value. In the design of a cooling circuit, often due to insufficient flow of the cooling medium leaving the cooling effect is reduced; without the cooling circuit design, the seal cavity often as harbored in the air and cause mechanical seal dry friction condition. In both cases, the movement of the mechanical seal sealing temperature is too high and accelerated wear, resulting in seal failure.
5, the use of a single spring mechanical seals ignored when spring pump rotor rotation direction and the direction of rotation correct combination also occurs. Or design without instructions or assembly negligence, failed to do so because of the rotation of the rotor mechanical seal leaving but on the contrary increase the spring force, resulting in the ring and stationary ring friction pairs formed insufficient pressure leak.
6, bearing severe wear or damage, so that axial movement of the shaft produce severe, but also one of the reasons mechanical seal leakage. With the scientific and technological development, new marker cable ties and sealing materials, emerging forms, which is bound to the pump seal technology have a direct impact and promoted. Long life, zero leakage pump products in a growing number of occasions to get promotion and application.
1, the mechanical seal material selection inappropriate. Mechanical seal material and the transmission medium does not match. In operation, the sealing element will soon be corrosion, dissolution or wear, thus losing the sealing capability. Therefore, according to the nature of the transmission medium and the choice of the mechanical seal material is to ensure its sealing function and the normal life of the prerequisites.
2, the mechanical seal flush condition does not meet the design requirements. In conveying easy to crystallize or fine particles of the medium, there must be a certain pressure and a certain flow of fluid to wash, or their crystals or particles will accelerate the sealing wear and affect the sealing of worn automatic compensation leak. Therefore, according to the nature of the transmission medium not only to configure the appropriate flushing lines, but also to install a monitoring and regulation instruments and devices to ensure that fluid pressure and flow to meet the design requirements, in order to maintain the normal operation of the mechanical black cable ties, which is often overlooked by users.
3, each of the mechanical seal can withstand the pressure is limited, due to the seal chamber pressure measurement are not allowed, resulting in the seal chamber pressure exceeds the mechanical seal can withstand the pressure of the leak, is a common sealing One reason for failure.
4, the mechanical seal operating temperature can not exceed the specified value. In the design of a cooling circuit, often due to insufficient flow of the cooling medium leaving the cooling effect is reduced; without the cooling circuit design, the seal cavity often as harbored in the air and cause mechanical seal dry friction condition. In both cases, the movement of the mechanical seal sealing temperature is too high and accelerated wear, resulting in seal failure.
5, the use of a single spring mechanical seals ignored when spring pump rotor rotation direction and the direction of rotation correct combination also occurs. Or design without instructions or assembly negligence, failed to do so because of the rotation of the rotor mechanical seal leaving but on the contrary increase the spring force, resulting in the ring and stationary ring friction pairs formed insufficient pressure leak.
6, bearing severe wear or damage, so that axial movement of the shaft produce severe, but also one of the reasons mechanical seal leakage. With the scientific and technological development, new marker cable ties and sealing materials, emerging forms, which is bound to the pump seal technology have a direct impact and promoted. Long life, zero leakage pump products in a growing number of occasions to get promotion and application.
2013年11月4日星期一
Hydraulic equipment damaged by the impact of seals
Mechanical processing industry, hydraulic transmission is widely used, such as lathes and other types of semi-automatic hydraulic transmission . These machines during use , such as the impact of frequent , reptiles and other faults , diagnostic repair, often in the hydraulic control components ( such as various types of pumps, valves ) can not find the cause of the malfunction , resulting in maintenance trouble. The final such failure or normally found on the actuator causes the cylinder piston sealing element due to severe wear . Such phenomena especially "O" ring seal see more .
Example 1: a CE7120 hydraulic copying lathe, turret profiling occurs in the work cited by the sword turn longitudinal feed line cutting die cutter , resulting knife fight , scrap living phenomenon frequently, the machine does not work.
Inspection and Maintenance : Check no fault of the hydraulic control components , maintenance work one o'clock into blind spots. Overhauling vertical turret tank, found that the piston seal "O" ring seal has been polished cylindrical , cylindrical piston also found substandard size requirements ( genus machine tool manufacturing reasons ) , the diameter direction is less than standard size 0.8mm, piston and cylinder body clearance large, causing vertical cylinder two chambers communicate channeling oil . Maintenance, and replacement of the piston passing "O" -ring after the die cutter machine troubleshooting. Analysis of the reasons cited in the profiling tool holder in place of the instantaneous line of the sword , the whole holder to receive a momentum F ', the force is decomposed F'1 a horizontal force acting on the cylinder piston rod longitudinal direction , at the same time , the solenoid valve 34E1-25B work turned vertical cylinder rod chamber pressure oil chamber connected rodless return oil control valve , the piston rod chamber by the force F by the two partially completed , one for F'1, the other is F1 = A1P1, where A1 is rodless chamber force area , then F = F'1 + F1. Under normal circumstances , the piston under the action of the force F rod chamber began to move , as incompressible hydraulic oil , hydraulic oil pressure rodless abrupt increase cavity to form a back pressure piston , the piston control valve according to the force balance it is set to go steady speed knife . The moment due % F'1 role in longitudinal cylinder chamber pressure P2 will be greater than P1. In practice, the two-chamber cylinder gap channeling due to the P2> P1 moments, hydraulic fluid from the high pressure zone with rod chamber rod chamber to the low pressure area flow trends , liquidity , once produced , P2 reduced , P1 rises , F1 increase large , unbalanced force piston , the piston driven turret quickly moves to the rod chamber . And moments later, the end result of profiling tool slide downward acting on the piston in the cylinder longitudinal horizontal thrust F'1 disappear on their own fast-moving piston end , take the knife stabilized turret , Fixed Length plastic seal red knife phenomenon ends.
Example 2: a CB3463-1 semi-automatic programmable hexagon turret lathes, during use , the emergence of the turret feed rate can not adjust the failure phenomenon , globe valve 2 is closed there is still crawling, pediment , and has been to bottom of the tank to stop the machine does not work properly .
Inspection and Maintenance : Inspect all hydraulic control components , especially the governor components have not found any problems. Replace some of the control valve , the failure persists . After dismantling the cylinder after the discovery piston "O" ring seal badly worn , so that the two chambers of hydraulic oil cylinder channeling each year. Analysis of the reasons , because "O" -ring wear, cylinder rod chamber and the rod chamber gap increases interoperability, when closing valve control valve 3 or 2:00 , it means cutting off the cylinder rod chamber oil return road. Theoretically , the pressure oil into the cylinder rod chamber when the piston is formed without a force F , the piston rod chamber to move the trend, as the cylinder rod chamber back to the oil off the rapid formation of the oil cavity back pressure , so that the force balance across the piston stationary , F a = F no time , no fluid pressure chamber due to the piston force different size and different, that is, P a > P no .
In practice, a gap is formed due to the two chambers communicate with each cylinder , the cylinder chamber with pressure oil from the high pressure region to the low flow area trends , mobile one generation,security seals a lower chamber pressure P , P without elevated ends of the thrust acting on the piston F No > F Yes, loss of balance piston rod chamber to move to find a new balance . And so forth, the piston has been moved to an external force barrier to stop. The phenomenon of the maintenance work to the machine brought great impact , replace the cylinder piston "O" ring seal , the machine fault elimination , running back to normal.
Example 1: a CE7120 hydraulic copying lathe, turret profiling occurs in the work cited by the sword turn longitudinal feed line cutting die cutter , resulting knife fight , scrap living phenomenon frequently, the machine does not work.
Inspection and Maintenance : Check no fault of the hydraulic control components , maintenance work one o'clock into blind spots. Overhauling vertical turret tank, found that the piston seal "O" ring seal has been polished cylindrical , cylindrical piston also found substandard size requirements ( genus machine tool manufacturing reasons ) , the diameter direction is less than standard size 0.8mm, piston and cylinder body clearance large, causing vertical cylinder two chambers communicate channeling oil . Maintenance, and replacement of the piston passing "O" -ring after the die cutter machine troubleshooting. Analysis of the reasons cited in the profiling tool holder in place of the instantaneous line of the sword , the whole holder to receive a momentum F ', the force is decomposed F'1 a horizontal force acting on the cylinder piston rod longitudinal direction , at the same time , the solenoid valve 34E1-25B work turned vertical cylinder rod chamber pressure oil chamber connected rodless return oil control valve , the piston rod chamber by the force F by the two partially completed , one for F'1, the other is F1 = A1P1, where A1 is rodless chamber force area , then F = F'1 + F1. Under normal circumstances , the piston under the action of the force F rod chamber began to move , as incompressible hydraulic oil , hydraulic oil pressure rodless abrupt increase cavity to form a back pressure piston , the piston control valve according to the force balance it is set to go steady speed knife . The moment due % F'1 role in longitudinal cylinder chamber pressure P2 will be greater than P1. In practice, the two-chamber cylinder gap channeling due to the P2> P1 moments, hydraulic fluid from the high pressure zone with rod chamber rod chamber to the low pressure area flow trends , liquidity , once produced , P2 reduced , P1 rises , F1 increase large , unbalanced force piston , the piston driven turret quickly moves to the rod chamber . And moments later, the end result of profiling tool slide downward acting on the piston in the cylinder longitudinal horizontal thrust F'1 disappear on their own fast-moving piston end , take the knife stabilized turret , Fixed Length plastic seal red knife phenomenon ends.
Example 2: a CB3463-1 semi-automatic programmable hexagon turret lathes, during use , the emergence of the turret feed rate can not adjust the failure phenomenon , globe valve 2 is closed there is still crawling, pediment , and has been to bottom of the tank to stop the machine does not work properly .
Inspection and Maintenance : Inspect all hydraulic control components , especially the governor components have not found any problems. Replace some of the control valve , the failure persists . After dismantling the cylinder after the discovery piston "O" ring seal badly worn , so that the two chambers of hydraulic oil cylinder channeling each year. Analysis of the reasons , because "O" -ring wear, cylinder rod chamber and the rod chamber gap increases interoperability, when closing valve control valve 3 or 2:00 , it means cutting off the cylinder rod chamber oil return road. Theoretically , the pressure oil into the cylinder rod chamber when the piston is formed without a force F , the piston rod chamber to move the trend, as the cylinder rod chamber back to the oil off the rapid formation of the oil cavity back pressure , so that the force balance across the piston stationary , F a = F no time , no fluid pressure chamber due to the piston force different size and different, that is, P a > P no .
In practice, a gap is formed due to the two chambers communicate with each cylinder , the cylinder chamber with pressure oil from the high pressure region to the low flow area trends , mobile one generation,security seals a lower chamber pressure P , P without elevated ends of the thrust acting on the piston F No > F Yes, loss of balance piston rod chamber to move to find a new balance . And so forth, the piston has been moved to an external force barrier to stop. The phenomenon of the maintenance work to the machine brought great impact , replace the cylinder piston "O" ring seal , the machine fault elimination , running back to normal.
These aspects of mechanical seals how to do these problems
Graphite ring ( or ceramic ) fracture
PTFE o-ring friction is small , stationary ring with snap ring rotation , the contact pin after the break.
Symptoms at the pin groove cracking or destroyed a graphite ring .
Corrective measures making pin sets ; self-locking cable ties using other types of seals or static ring structure.
o-ring overheating
Usually because the heat conduction unfavorable end result .
Symptoms rubber ring hardening and cracking. PTFE blue or black. Near the seal face the worst .
Corrective measures checking seal design ; Check and improve circulation status .
o-ring extrusion
o-ring part is forced through a small gap . Assembly or assembly of components when the force is too large, or the sealing gap is too large .
Symptoms o-ring is cut or torn skin .
Corrective Action Check the assembly method .
o-ring corrosion, swelling
Symptoms inappropriate material selection occurs when swelling , fracture , deformation and other faults.
Corrective measures based on the actual conditions, re-select the material .
Graphite erosion ( element )
When the fluid pressure is too large or contains grinding particles .
Symptoms of flushing fluid inlet is on the element at a erosion pits .
Corrective measures to reduce the fluid pressure ; using hydrocyclones .
Evacuated
System pressure fluctuations or cavitation generated at the seal faces
Symptoms: plastic security seals the dregs at the end round and round Zhoucheng Bo striated , 0 laps extrusion, static ring from the bit .
Corrective Action: change the system operation process , increase the amount of rinse
PTFE o-ring friction is small , stationary ring with snap ring rotation , the contact pin after the break.
Symptoms at the pin groove cracking or destroyed a graphite ring .
Corrective measures making pin sets ; self-locking cable ties using other types of seals or static ring structure.
o-ring overheating
Usually because the heat conduction unfavorable end result .
Symptoms rubber ring hardening and cracking. PTFE blue or black. Near the seal face the worst .
Corrective measures checking seal design ; Check and improve circulation status .
o-ring extrusion
o-ring part is forced through a small gap . Assembly or assembly of components when the force is too large, or the sealing gap is too large .
Symptoms o-ring is cut or torn skin .
Corrective Action Check the assembly method .
o-ring corrosion, swelling
Symptoms inappropriate material selection occurs when swelling , fracture , deformation and other faults.
Corrective measures based on the actual conditions, re-select the material .
Graphite erosion ( element )
When the fluid pressure is too large or contains grinding particles .
Symptoms of flushing fluid inlet is on the element at a erosion pits .
Corrective measures to reduce the fluid pressure ; using hydrocyclones .
Evacuated
System pressure fluctuations or cavitation generated at the seal faces
Symptoms: plastic security seals the dregs at the end round and round Zhoucheng Bo striated , 0 laps extrusion, static ring from the bit .
Corrective Action: change the system operation process , increase the amount of rinse
2013年11月3日星期日
Industrial pump mechanical seal failure and these reasons
Vibration is too large
Mechanical seals vibration is too large , resulting in loss of seal. But the reasons for larger vibration mechanical seal mechanical seal itself is often not the cause , the other parts of the pump is the source of vibration , such as shaft design is unreasonable ,container seals processing reasons, lack of precision bearings , couplings parallelism poor, radial force and other reasons .
Pump cavitation causes
Since the unit and the pump inlet system operation unreasonable cavitation performance is not good, the high speed of the pump , the pump inlet localized cavitation , cavitation occurs, the water will bubble one hand, it will impact the mechanical seal faces an outer surface , so that the surface damage ; hand side anastomosis ring movement causes a flow membrane also contains bubbles can form a stable flow of film, resulting in movement of the ring fit surface friction, the mechanical seal device is damaged .
Lack of precision machining
Machining accuracy is not enough , there are many reasons , some precision mechanical seal itself is not enough, the reason for this is easy to arouse people's attention , but also easy to find. But sometimes the other components of the pump is not precision , the reason for this is not likely to cause people 's attention . For example: shaft , bushings ,security seals pump, seal chamber to increase accuracy is not enough other reasons . The presence of these reasons, the sealing effect of the mechanical seal is very unfavorable .
Mechanical seals vibration is too large , resulting in loss of seal. But the reasons for larger vibration mechanical seal mechanical seal itself is often not the cause , the other parts of the pump is the source of vibration , such as shaft design is unreasonable ,container seals processing reasons, lack of precision bearings , couplings parallelism poor, radial force and other reasons .
Pump cavitation causes
Since the unit and the pump inlet system operation unreasonable cavitation performance is not good, the high speed of the pump , the pump inlet localized cavitation , cavitation occurs, the water will bubble one hand, it will impact the mechanical seal faces an outer surface , so that the surface damage ; hand side anastomosis ring movement causes a flow membrane also contains bubbles can form a stable flow of film, resulting in movement of the ring fit surface friction, the mechanical seal device is damaged .
Lack of precision machining
Machining accuracy is not enough , there are many reasons , some precision mechanical seal itself is not enough, the reason for this is easy to arouse people's attention , but also easy to find. But sometimes the other components of the pump is not precision , the reason for this is not likely to cause people 's attention . For example: shaft , bushings ,security seals pump, seal chamber to increase accuracy is not enough other reasons . The presence of these reasons, the sealing effect of the mechanical seal is very unfavorable .
The transformation of plant water pump seal
Rotating machinery as a pump , the shaft and the casing there is a gap between the necessity , in order to prevent discharge of liquid out of the pump or leakage of air into the pump ( inlet of vacuum ) , generally between the shaft and the pump casing provided with a shaft sealing device . Recent years due to the continuous development of high-temperature high-pressure pump , the pump seal problems have an impact on safety is one important factor . Shaft sealing device currently used generally have the following forms: packing seal , mechanical seals, labyrinth seals, floating ring seal , and for many of the low-pressure pump power plant , generally soft packing seal .
Multi-use asbestos , carbon fibers, PTFE resin and other materials woven into a square or circle. Soft packing seal has a versatile, cheap and so on . Plus the usual soft fillers such as leaking water pump , generally tight gland plate method . If not , you must stop the pump again for filler. And soft filler cycle is generally short and right sleeve wear larger , which makes routine maintenance increases, and not the economy. At this stage able to use other methods to use it instead of packing ? Foreign experience combined with China 's actual thermal power plant , the available injectable filler gun wadding method to replace the use of packing .
Soft packing filler gun injection principle is to pulpy soft packing high pressure pump filler injected into the chamber ,releasable cable tie which was replaced rope -like packing. Other parts of the packing room remains unchanged .
A transformation step
Because at this stage low-pressure pumps and more thermal power plant with packing seal , which faces an example of how to transform based on the original problem , based on experience and are summarized below .
1.1 clean packing room
Thoroughly clean the pump before the transformation good original packing room , does not allow any impurities and dirt. If seal ring, can be abandoned. This work must be carried Uncovery in order to save time and materials , it is best when the pump overhaul . This allows the overhaul and reconstruction synchronization.
1.2 water pump cover drilling
In order to inject fillers, must cover the installation of the injection hole connector. Joints need special processing, the threads need to cooperate with the filler gun fittings and connectors to be processed gland , for a water pump seal , seal tube can be removed directly in the water seal on the drilling and tapping.
1.3 plus packing
In order to prevent leakage and internal leakage filler is required at each end of the packing chamber before and after the installation of a circle packing, you can add carbon fiber packing or PTFE packing.security seal labels Because it is Uncovery added packing, so care must be taken plus packing clearance fit to close .
1.4 plus filler
First hand pressed into the filler packing room , without too tight. Then close the pump cover with gland packing rope , and then put the gun filler filler can be injected under pressure . At this time packing should be tight .
Multi-use asbestos , carbon fibers, PTFE resin and other materials woven into a square or circle. Soft packing seal has a versatile, cheap and so on . Plus the usual soft fillers such as leaking water pump , generally tight gland plate method . If not , you must stop the pump again for filler. And soft filler cycle is generally short and right sleeve wear larger , which makes routine maintenance increases, and not the economy. At this stage able to use other methods to use it instead of packing ? Foreign experience combined with China 's actual thermal power plant , the available injectable filler gun wadding method to replace the use of packing .
Soft packing filler gun injection principle is to pulpy soft packing high pressure pump filler injected into the chamber ,releasable cable tie which was replaced rope -like packing. Other parts of the packing room remains unchanged .
A transformation step
Because at this stage low-pressure pumps and more thermal power plant with packing seal , which faces an example of how to transform based on the original problem , based on experience and are summarized below .
1.1 clean packing room
Thoroughly clean the pump before the transformation good original packing room , does not allow any impurities and dirt. If seal ring, can be abandoned. This work must be carried Uncovery in order to save time and materials , it is best when the pump overhaul . This allows the overhaul and reconstruction synchronization.
1.2 water pump cover drilling
In order to inject fillers, must cover the installation of the injection hole connector. Joints need special processing, the threads need to cooperate with the filler gun fittings and connectors to be processed gland , for a water pump seal , seal tube can be removed directly in the water seal on the drilling and tapping.
1.3 plus packing
In order to prevent leakage and internal leakage filler is required at each end of the packing chamber before and after the installation of a circle packing, you can add carbon fiber packing or PTFE packing.security seal labels Because it is Uncovery added packing, so care must be taken plus packing clearance fit to close .
1.4 plus filler
First hand pressed into the filler packing room , without too tight. Then close the pump cover with gland packing rope , and then put the gun filler filler can be injected under pressure . At this time packing should be tight .
2013年11月1日星期五
Correctly handle automotive sealing problems
Automotive sealing strip (automobile rubber seal strip) is one of the important parts car , widely used in doors, windows , body , seats, sunroof, and other parts of the engine compartment and trunk , with a waterproof, sealing, noise , dust , frost , shock absorption , warmth and energy conservation an important role. It must have a strong tensile strength , good flexibility , but also good heat resistance and resistance to aging. In order to ensure the fastening strips and profiles , strips and profiles section structure dimensions must match .
Fix the sealing flange in the vehicle door , the seal should be noted that repair damaged flanges , flange accurately restore the original shape. To carry out the repair after the door seal inspection, the inspection method is: put a hard disk in a sealed position, shut the door , and then pull the paper , according to the Rally to determine the size seal is good . If the force required to pull the paper too much explanation sealed tight, this will affect the doors close properly , and also due to deformation of the seal over the Omo faster mourning for sealing performance ; if the force required to pull the paper too small , indicating bad seal doors wind does not often appear rain phenomenon. When replacing the door must pay attention to the inner and outer door panels in a new office painted folding plastic flange bite and put some punch hole left when the small craft with the base tape blocked .
In the repair of automotive line , should all body holes , holes worn harness ring is mounted at the place, not only because these seals from the seal, but also play a protective role in the harness . If the seal is damaged or harness can be rotated or ran seals , replace the metal security seals, and compares it with the body holes , hole assembly firmly secure the harness is good .
In the window glass is damaged , changing with the same curvature as the original glass window glass , while the glass to check the guide groove and seal for damage. Because windows often reply after repair is less than its original shape , therefore , when in addition to ensure easy pulling or lifting the window glass , but also pay attention to the window glass in the windows closed after four weeks of the seal.
In changing the roof , the roof should be in place around the lamination coated conductive sealant, after a good to be welded seams in the water tank and folding over the painted plastic , which not only helps the body seal , prevents the body due to more water to produce the weld flange early rust. Assembling the door when the door below the window paste an entire inner panel sealing barrier film , if not forming a seal barrier film , you can use ordinary plastic instead of paper , and then affix the seal spacer film compaction , and finally for interior panels production assembly .
When replacing the entire body , in addition to each of these projects should be completed outside , but also in the lap portion of the weld joints on both coated with sealant layer thickness should be about 1mm, and may not have virtual sticky layer , bubbles and other defects ; should be at the Flap Flap special plastic coated ; across the floor surface and the lower surface of the front cover should be coated 3mm-4mm elastic coatings and anti-corrosion coating ; on the floor surface and the front elevation to paste the plate surface noise, heat , vibration damping film , colored cable ties then covered insulation blankets block , and finally covered with carpets or fitted with decorative flooring. These measures can greatly enhance the sealing and the vehicle speed slows down corrosion of the body , but also can greatly enhance comfort.
Fix the sealing flange in the vehicle door , the seal should be noted that repair damaged flanges , flange accurately restore the original shape. To carry out the repair after the door seal inspection, the inspection method is: put a hard disk in a sealed position, shut the door , and then pull the paper , according to the Rally to determine the size seal is good . If the force required to pull the paper too much explanation sealed tight, this will affect the doors close properly , and also due to deformation of the seal over the Omo faster mourning for sealing performance ; if the force required to pull the paper too small , indicating bad seal doors wind does not often appear rain phenomenon. When replacing the door must pay attention to the inner and outer door panels in a new office painted folding plastic flange bite and put some punch hole left when the small craft with the base tape blocked .
In the repair of automotive line , should all body holes , holes worn harness ring is mounted at the place, not only because these seals from the seal, but also play a protective role in the harness . If the seal is damaged or harness can be rotated or ran seals , replace the metal security seals, and compares it with the body holes , hole assembly firmly secure the harness is good .
In the window glass is damaged , changing with the same curvature as the original glass window glass , while the glass to check the guide groove and seal for damage. Because windows often reply after repair is less than its original shape , therefore , when in addition to ensure easy pulling or lifting the window glass , but also pay attention to the window glass in the windows closed after four weeks of the seal.
In changing the roof , the roof should be in place around the lamination coated conductive sealant, after a good to be welded seams in the water tank and folding over the painted plastic , which not only helps the body seal , prevents the body due to more water to produce the weld flange early rust. Assembling the door when the door below the window paste an entire inner panel sealing barrier film , if not forming a seal barrier film , you can use ordinary plastic instead of paper , and then affix the seal spacer film compaction , and finally for interior panels production assembly .
When replacing the entire body , in addition to each of these projects should be completed outside , but also in the lap portion of the weld joints on both coated with sealant layer thickness should be about 1mm, and may not have virtual sticky layer , bubbles and other defects ; should be at the Flap Flap special plastic coated ; across the floor surface and the lower surface of the front cover should be coated 3mm-4mm elastic coatings and anti-corrosion coating ; on the floor surface and the front elevation to paste the plate surface noise, heat , vibration damping film , colored cable ties then covered insulation blankets block , and finally covered with carpets or fitted with decorative flooring. These measures can greatly enhance the sealing and the vehicle speed slows down corrosion of the body , but also can greatly enhance comfort.
Gasket leaks cause analysis
The gasket leakage :
General gasket leaks , there are four forms: interface leak , leak penetration , diffusion leaks, damage leak.
Penetration leak: soft gasket material because the material is mostly fiber, easy to dip appropriate media , in particular pressure . tie wraps Due to capillary phenomenon, the medium will penetrate into the low pressure side to form infiltration.
Interface Leak : The interface is not as gasket compression flange surface finish combined with improper flange deformation etc will leak in the sealed interface . For interface World leakage , the use of padded material can be clamped against the flange surface .
Destruction Leakage: sealing parts relatively poor working conditions , thermal deformation, often affected by vibration, shock , improper installation , fastening force is too large , used repeatedly , deformation , stress concentration, fatigue strength and damage than the material aging , deterioration etc will cause damage leak. This leakage causes the greatest impact hazard is also large , to strengthen prevention.
Diffusion Leakage: poor concentration , driven by the media or by sealing the gap sealing material produced by mass transfer and capillary leak . Diffusion is the result of molecular motion , and not one-way. Minimal pressure or vacuum in a sealed state , or sealed nitrogen, high security seal hydrogen and other permeable substances, as well as highly toxic , radioactive substances should pay special attention penetration and proliferation of two kinds of leaks.
General gasket leaks , there are four forms: interface leak , leak penetration , diffusion leaks, damage leak.
Penetration leak: soft gasket material because the material is mostly fiber, easy to dip appropriate media , in particular pressure . tie wraps Due to capillary phenomenon, the medium will penetrate into the low pressure side to form infiltration.
Interface Leak : The interface is not as gasket compression flange surface finish combined with improper flange deformation etc will leak in the sealed interface . For interface World leakage , the use of padded material can be clamped against the flange surface .
Destruction Leakage: sealing parts relatively poor working conditions , thermal deformation, often affected by vibration, shock , improper installation , fastening force is too large , used repeatedly , deformation , stress concentration, fatigue strength and damage than the material aging , deterioration etc will cause damage leak. This leakage causes the greatest impact hazard is also large , to strengthen prevention.
Diffusion Leakage: poor concentration , driven by the media or by sealing the gap sealing material produced by mass transfer and capillary leak . Diffusion is the result of molecular motion , and not one-way. Minimal pressure or vacuum in a sealed state , or sealed nitrogen, high security seal hydrogen and other permeable substances, as well as highly toxic , radioactive substances should pay special attention penetration and proliferation of two kinds of leaks.
2013年10月31日星期四
Valve gasket damaged damaged bitter pit large tanker drivers
8 pm, Mengjin County Baihe Town territory Zhengsan Gong Lu Meng Road, near the buckle tanker spill occurred , but fortunately no casualties .
16:00 the day before , container seals a formaldehyde solution tanker transportation in Bangladesh village a big buckle road slope sections Mizoguchi leak , the county public security fire department rushed to the scene after the alarm .
Police on the scene saw the leaked formaldehyde solution to form a ditch along the roadside about 400 meters and a width of 1 meter trickle. In the relevant departments under the coordination of the car belongs transferred to another car company vehicle accidents within the formaldehyde solution pumped . Field staff to disclose rubbed salt formaldehyde solution and covered with mud after clearing, collection .
It is understood that the car is equipped with 10 tons of formaldehyde solution , because the tanker at the bottom of a valve gasket is damaged, resulting inside about 300 kg , containing 30% aqueous solution of formaldehyde leak. Formaldehyde is a kind of colorless gas with strong pungent odor , soluble in water , alcohol and ether .self-locking cable ties Formaldehyde is gaseous at room temperature , usually in the form of an aqueous solution .
Currently, the leaked scene disposal, the road returned to normal traffic .
16:00 the day before , container seals a formaldehyde solution tanker transportation in Bangladesh village a big buckle road slope sections Mizoguchi leak , the county public security fire department rushed to the scene after the alarm .
Police on the scene saw the leaked formaldehyde solution to form a ditch along the roadside about 400 meters and a width of 1 meter trickle. In the relevant departments under the coordination of the car belongs transferred to another car company vehicle accidents within the formaldehyde solution pumped . Field staff to disclose rubbed salt formaldehyde solution and covered with mud after clearing, collection .
It is understood that the car is equipped with 10 tons of formaldehyde solution , because the tanker at the bottom of a valve gasket is damaged, resulting inside about 300 kg , containing 30% aqueous solution of formaldehyde leak. Formaldehyde is a kind of colorless gas with strong pungent odor , soluble in water , alcohol and ether .self-locking cable ties Formaldehyde is gaseous at room temperature , usually in the form of an aqueous solution .
Currently, the leaked scene disposal, the road returned to normal traffic .
Valve gasket damaged damaged bitter pit large tanker drivers
8 pm, Mengjin County Baihe Town territory Zhengsan Gong Lu Meng Road, near the buckle tanker spill occurred , but fortunately no casualties .
16:00 the day before , container seals a formaldehyde solution tanker transportation in Bangladesh village a big buckle road slope sections Mizoguchi leak , the county public security fire department rushed to the scene after the alarm .
Police on the scene saw the leaked formaldehyde solution to form a ditch along the roadside about 400 meters and a width of 1 meter trickle. In the relevant departments under the coordination of the car belongs transferred to another car company vehicle accidents within the formaldehyde solution pumped . Field staff to disclose rubbed salt formaldehyde solution and covered with mud after clearing, collection .
It is understood that the car is equipped with 10 tons of formaldehyde solution , because the tanker at the bottom of a valve gasket is damaged, resulting inside about 300 kg , containing 30% aqueous solution of formaldehyde leak. Formaldehyde is a kind of colorless gas with strong pungent odor , soluble in water , alcohol and ether .self-locking cable ties Formaldehyde is gaseous at room temperature , usually in the form of an aqueous solution .
Currently, the leaked scene disposal, the road returned to normal traffic .
16:00 the day before , container seals a formaldehyde solution tanker transportation in Bangladesh village a big buckle road slope sections Mizoguchi leak , the county public security fire department rushed to the scene after the alarm .
Police on the scene saw the leaked formaldehyde solution to form a ditch along the roadside about 400 meters and a width of 1 meter trickle. In the relevant departments under the coordination of the car belongs transferred to another car company vehicle accidents within the formaldehyde solution pumped . Field staff to disclose rubbed salt formaldehyde solution and covered with mud after clearing, collection .
It is understood that the car is equipped with 10 tons of formaldehyde solution , because the tanker at the bottom of a valve gasket is damaged, resulting inside about 300 kg , containing 30% aqueous solution of formaldehyde leak. Formaldehyde is a kind of colorless gas with strong pungent odor , soluble in water , alcohol and ether .self-locking cable ties Formaldehyde is gaseous at room temperature , usually in the form of an aqueous solution .
Currently, the leaked scene disposal, the road returned to normal traffic .
Wafer soft seal butterfly valve characteristics
New features and butterfly valve in the course of a problem :
Currently, soft seal butterfly valve as a piping system used to achieve off and flow control components, has been in the petroleum, chemical, metallurgy, water and electricity , and many other fields has been very widely used . In the well-known butterfly valve technology , the sealing forms enclosed structure, sealing material for rubber , PTFE and so on. Restrictions due to structural features , suited high temperature, high pressure and corrosion resistance, abrasion resistance and other industries. Present a more advanced butterfly valve is a three eccentricity metal hard luggage seals butterfly valve, valve and seat components for the piece , seat sealing surface layer welding temperature, corrosion resistant alloys. Multilayer soft stacked ring fixed to the valve plate, this butterfly valve in comparison with the conventional high temperature , easy operation, open and close without friction, closed with the transmission of the torque increases to compensate for sealing , improved valve sealing performance and durability advantages .
One , as soft and hard stacked ring fixed in the valve plate, when the valve plate normally open state media, the formation of a positive sealing surface erosion, metal sheets laminated in soft sealing tape subject to erosion , direct impact on seal performance.
Second, by the structural constraints of the structure do not meet the following diameter DN200 valves, because the overall structure of the valve plate is too thick, large flow resistance .
Third, because the principle of three eccentric structure , the sealing surface of the valve plate seal between the valve seat is on the transmission of torque to the valve plate is pressed against the valve seat . Positive flow state, the higher the pressure medium sealed tight squeeze . When the flow channel upstream medium with media pressure valve plate and valve seat pressure between the units is less than the medium pressure, the security stickers started to leak .
Currently, soft seal butterfly valve as a piping system used to achieve off and flow control components, has been in the petroleum, chemical, metallurgy, water and electricity , and many other fields has been very widely used . In the well-known butterfly valve technology , the sealing forms enclosed structure, sealing material for rubber , PTFE and so on. Restrictions due to structural features , suited high temperature, high pressure and corrosion resistance, abrasion resistance and other industries. Present a more advanced butterfly valve is a three eccentricity metal hard luggage seals butterfly valve, valve and seat components for the piece , seat sealing surface layer welding temperature, corrosion resistant alloys. Multilayer soft stacked ring fixed to the valve plate, this butterfly valve in comparison with the conventional high temperature , easy operation, open and close without friction, closed with the transmission of the torque increases to compensate for sealing , improved valve sealing performance and durability advantages .
One , as soft and hard stacked ring fixed in the valve plate, when the valve plate normally open state media, the formation of a positive sealing surface erosion, metal sheets laminated in soft sealing tape subject to erosion , direct impact on seal performance.
Second, by the structural constraints of the structure do not meet the following diameter DN200 valves, because the overall structure of the valve plate is too thick, large flow resistance .
Third, because the principle of three eccentric structure , the sealing surface of the valve plate seal between the valve seat is on the transmission of torque to the valve plate is pressed against the valve seat . Positive flow state, the higher the pressure medium sealed tight squeeze . When the flow channel upstream medium with media pressure valve plate and valve seat pressure between the units is less than the medium pressure, the security stickers started to leak .
2013年10月28日星期一
Currently on the market often posing Corner There are three types of plastic glue
Strength aluminum alloy doors and sealing the corners of aluminum doors and windows as long as the use of special glue to set angle, but unfortunately most of the windows and doors factory and developers, as well as related administrative departments architectural design, supervision and other units did not really recognize the special Corner plastic windows and doors in improving the overall quality of the important role. Some assembly plant doors and windows do not use glue or wrongly Corner glass adhesive, structural adhesive, such as epoxy glue aluminum doors and windows dedicated Corner glue in use. Currently on the market often posing Corner adhesive glue into three categories:
1, glass, plastic, also known as silicone sealant; poor adhesion on aluminum, poor weather, easy to aging, low hardness, elasticity is too large, curing gel does not swell, can not make the corner yard stick closely with the cavity then become one.
2, structural adhesive for bonding aluminum poor, long curing time, products and more smell, does not swell when cured, can not produce high strength.
3, after curing epoxy adhesive inelastic, unable to adapt to the form of microseismic, easy crisp and broken, Corner after long-term strength is not enough, will produce cracking, dregs phenomenon.
Why do we have to use a dedicated advocate Corner gum? Because of special aluminum alloy doors and windows Corner glue has the following characteristics:
1, colloids are modified polyurethane-based adhesives, solvent-free, in line with environmental requirements.
2, initial curing time is short, about 10 minutes, will help improve production efficiency. Divided into single, two-component two kinds, more suitable for "Corner glue and corner connectors dispensing whole" two kinds of process requirements.
3, high hardness after curing, but not brittle, with low elasticity and excellent waterproof performance, so that angle code and section ductile adhesive wall connections, which make up, various parts of the corner of the window to reduce deformation, cracking conditions an effective solution to the problem of leakage corner windows and doors.
4, one-component adhesive glue is completely cured Corner, Corner profiles cavity with an effective part of the shear strength of the adhesive can be achieved 10.3N/MM2, component Corner Shear strength can reach 18N/MM2, greatly enhanced strength corner of the window. That is, ordinary 60 series of profiles of the shear strength can exceed Cutaway.
5, colloidal slightly foaming during the curing process, expanded, forming metal to metal between the elastic pad, the effective transmission of forces weaken, play a shock, the cushion effect.
6, weather resistance, the ability of -40 ° C +80 ° C temperature variation, white or translucent gel, the gel will not play in the short yellow. Corner two-component glue in 230 ° C high temperature tolerance of 30 minutes, suitable for powder coating and other post-processing needs.
7, with special cleaning agent with a small amount of excess glue is easy to clean,Fixed Length plastic seals will not harm the surface profile of the coating and paint, environmental non-toxic.
The author believes that the current market a lot to promote the use of the German "Wei Shi" series Corner combination of gum and related ancillary products, aluminum doors and windows corner for structural reinforcement and sealed professionally designed to meet the requirements of various groups angle is aluminum door and window factory and the developers of the most sensible choice.
1, glass, plastic, also known as silicone sealant; poor adhesion on aluminum, poor weather, easy to aging, low hardness, elasticity is too large, curing gel does not swell, can not make the corner yard stick closely with the cavity then become one.
2, structural adhesive for bonding aluminum poor, long curing time, products and more smell, does not swell when cured, can not produce high strength.
3, after curing epoxy adhesive inelastic, unable to adapt to the form of microseismic, easy crisp and broken, Corner after long-term strength is not enough, will produce cracking, dregs phenomenon.
Why do we have to use a dedicated advocate Corner gum? Because of special aluminum alloy doors and windows Corner glue has the following characteristics:
1, colloids are modified polyurethane-based adhesives, solvent-free, in line with environmental requirements.
2, initial curing time is short, about 10 minutes, will help improve production efficiency. Divided into single, two-component two kinds, more suitable for "Corner glue and corner connectors dispensing whole" two kinds of process requirements.
3, high hardness after curing, but not brittle, with low elasticity and excellent waterproof performance, so that angle code and section ductile adhesive wall connections, which make up, various parts of the corner of the window to reduce deformation, cracking conditions an effective solution to the problem of leakage corner windows and doors.
4, one-component adhesive glue is completely cured Corner, Corner profiles cavity with an effective part of the shear strength of the adhesive can be achieved 10.3N/MM2, component Corner Shear strength can reach 18N/MM2, greatly enhanced strength corner of the window. That is, ordinary 60 series of profiles of the shear strength can exceed Cutaway.
5, colloidal slightly foaming during the curing process, expanded, forming metal to metal between the elastic pad, the effective transmission of forces weaken, play a shock, the cushion effect.
6, weather resistance, the ability of -40 ° C +80 ° C temperature variation, white or translucent gel, the gel will not play in the short yellow. Corner two-component glue in 230 ° C high temperature tolerance of 30 minutes, suitable for powder coating and other post-processing needs.
7, with special cleaning agent with a small amount of excess glue is easy to clean,Fixed Length plastic seals will not harm the surface profile of the coating and paint, environmental non-toxic.
The author believes that the current market a lot to promote the use of the German "Wei Shi" series Corner combination of gum and related ancillary products, aluminum doors and windows corner for structural reinforcement and sealed professionally designed to meet the requirements of various groups angle is aluminum door and window factory and the developers of the most sensible choice.
Gear pump mechanical seal shortcomings
1) is more complex, demanding for processing
2) Installation and replacement of cumbersome, requiring workers to have a certain level of technology
3) fortuitous accident occurred when handling more difficult.
Preparatory work before sealing the highest bid:
1) Check the mechanical seal models. Specifications to check whether the requirements of the design drawings, so parts (extraordinary is the sealing surface, secondary seal) for damage. Deformation. Cracks phenomenon, if defective and must be replaced or repaired
2) Check the mechanical seal with the size of the parts, roughness, parallel with the design requirements
3) Using a small spring mechanical vehicle seals should be checked small springs are the same length and rigidity
4) Check the host runout. Swing amount and around the degree of compliance with the technical requirements, the sealed chamber meets the installation scale, sealed cover and whether the axis perpendicular to the general requirements: Shaft runout is less than ± 0.5mm: axis swing amount (rotation ring seal point) is not greater than 0.06mm: maximum around the axis is not greater than 0.05mm: sealing cover gasket contact with the plane on the vertical centerline of the promise is not bad 0.03 ~ 0.05mm.
5) should be kept clean, the extraordinary is the rotating ring and the stationary ring seal surface and the secondary seal surface should be free of impurities. container seal Dust does not agree with unclean loosen the sealing surface.
6) does not agree with the percussion instruments sealing element. To prevent the seal is damaged.
2) Installation and replacement of cumbersome, requiring workers to have a certain level of technology
3) fortuitous accident occurred when handling more difficult.
Preparatory work before sealing the highest bid:
1) Check the mechanical seal models. Specifications to check whether the requirements of the design drawings, so parts (extraordinary is the sealing surface, secondary seal) for damage. Deformation. Cracks phenomenon, if defective and must be replaced or repaired
2) Check the mechanical seal with the size of the parts, roughness, parallel with the design requirements
3) Using a small spring mechanical vehicle seals should be checked small springs are the same length and rigidity
4) Check the host runout. Swing amount and around the degree of compliance with the technical requirements, the sealed chamber meets the installation scale, sealed cover and whether the axis perpendicular to the general requirements: Shaft runout is less than ± 0.5mm: axis swing amount (rotation ring seal point) is not greater than 0.06mm: maximum around the axis is not greater than 0.05mm: sealing cover gasket contact with the plane on the vertical centerline of the promise is not bad 0.03 ~ 0.05mm.
5) should be kept clean, the extraordinary is the rotating ring and the stationary ring seal surface and the secondary seal surface should be free of impurities. container seal Dust does not agree with unclean loosen the sealing surface.
6) does not agree with the percussion instruments sealing element. To prevent the seal is damaged.
2013年10月27日星期日
Experts discuss starter gel sealed lead-acid battery type font
"Start -type gel sealed lead acid battery technology Seminar " was held recently in Beijing , high security bolt seals State Department Counselor Xu Dingming , Deputy Director of Science and Technology Development Plan and other related departments Liu Jinlin leaders and experts attended the meeting.
According to the project responsible person Zhang Dianding introduction , development polluting silicone body battery , validated by the former State Science and Technology Commission as a national key new product plan and the Torch Program and get Guangxi Science and Technology Progress Award. Sealed lead-acid battery -starter colloidal silica sol is added to a water-soluble after formation within the cell, through specific charging method to achieve the electrolyte into the gel to improve the relative performance of the battery . The product testing by the state authorities , some indicators than the national standard .
State Department counselor Xu Dingming noted that the project is an energy storage device , storage device is a new national energy policy revolution important part , cable ties not from the energy conservation , energy security is inseparable from the region , the smart grid can not be separated . Experts say : starting gel sealed lead-acid battery type is mainly used in automobile starters , the technology can also be applied to areas such as energy storage , belonging to the new energy industry to reduce pollution of the environment , in line with national industrial policy, its technology has reached the leading domestic level .
According to the project responsible person Zhang Dianding introduction , development polluting silicone body battery , validated by the former State Science and Technology Commission as a national key new product plan and the Torch Program and get Guangxi Science and Technology Progress Award. Sealed lead-acid battery -starter colloidal silica sol is added to a water-soluble after formation within the cell, through specific charging method to achieve the electrolyte into the gel to improve the relative performance of the battery . The product testing by the state authorities , some indicators than the national standard .
State Department counselor Xu Dingming noted that the project is an energy storage device , storage device is a new national energy policy revolution important part , cable ties not from the energy conservation , energy security is inseparable from the region , the smart grid can not be separated . Experts say : starting gel sealed lead-acid battery type is mainly used in automobile starters , the technology can also be applied to areas such as energy storage , belonging to the new energy industry to reduce pollution of the environment , in line with national industrial policy, its technology has reached the leading domestic level .
New seals leak and cause analysis
Sometimes mechanical seal leakage , not due to leakage caused by face , but because ring, stationary ring seal or sleeve seal leak caused . For the following reasons :
Machine rubber seals leak
Actuating ring, stationary ring "O" type rubber seals, rubber finish is not enough because the hardness inappropriate , good elasticity , friction coefficient, geometry failure , heat resistance, corrosion resistance and other good reasons, often cause seal leakage .
Machine shaft seal ring in contact with leaking
When a sleeve repeated use in contact with ring seal and sleeve at the sleeve surface will have a rough grinding marks and spots , often caused by seal leakage . The main reasons are:
( 1) Since the rail car seals ring and the sleeve exists between the small amount of relative movement , or other hard abrasive grains embedded impurities into the softer seal . Produce a friction rub on the sleeve , and the sleeve surface without surface hardening treatment or processing of poor quality , resulting in wear and tear.
( 2 ) the result of friction rub , the metal surface passivation film sleeve damage present on the surface of the metal sleeve electrode potential difference , the formation of electrochemical corrosion. Also, because of the contact at the leak itself and in the micro crevice corrosion when they have the condition , therefore , the corrosion rate is higher . Furthermore , seal ring side in contact with the atmosphere , due to the presence of oxygen , more complex and harsh etching conditions , so wear marks and spots more obvious.
PTFE sealing ring group polytetramethylene used in the ring , due to the smaller coefficient of friction than the rubber , high finish , easy to move with the ring , thus , is better than the rubber seals . Rubber seals used in the stationary ring , due to good elasticity, low hardness, therefore , the reliability is better than the PTFE ring seal . Therefore, a reasonable choice of ring material is also very important, and we based on the specific circumstances of corrosion on the mechanical seal made the following adjustments: the media side stationary ring with Teflon rings or rubber ring temperature corrosion in the atmosphere quiet side always use rubber ring ring ; ring PTFE seals are generally used , the effect is more ideal .
Bushings eliminate fretting , except try to use the sleeve surface hardness, good corrosion resistance, and maternal affinity, high surface finish of better spraying spraying materials and processes , but also pay attention when installing bushings wear, timely replacement of bushings, new security seals, in many ways to ensure sealing reliability.
Machine rubber seals leak
Actuating ring, stationary ring "O" type rubber seals, rubber finish is not enough because the hardness inappropriate , good elasticity , friction coefficient, geometry failure , heat resistance, corrosion resistance and other good reasons, often cause seal leakage .
Machine shaft seal ring in contact with leaking
When a sleeve repeated use in contact with ring seal and sleeve at the sleeve surface will have a rough grinding marks and spots , often caused by seal leakage . The main reasons are:
( 1) Since the rail car seals ring and the sleeve exists between the small amount of relative movement , or other hard abrasive grains embedded impurities into the softer seal . Produce a friction rub on the sleeve , and the sleeve surface without surface hardening treatment or processing of poor quality , resulting in wear and tear.
( 2 ) the result of friction rub , the metal surface passivation film sleeve damage present on the surface of the metal sleeve electrode potential difference , the formation of electrochemical corrosion. Also, because of the contact at the leak itself and in the micro crevice corrosion when they have the condition , therefore , the corrosion rate is higher . Furthermore , seal ring side in contact with the atmosphere , due to the presence of oxygen , more complex and harsh etching conditions , so wear marks and spots more obvious.
PTFE sealing ring group polytetramethylene used in the ring , due to the smaller coefficient of friction than the rubber , high finish , easy to move with the ring , thus , is better than the rubber seals . Rubber seals used in the stationary ring , due to good elasticity, low hardness, therefore , the reliability is better than the PTFE ring seal . Therefore, a reasonable choice of ring material is also very important, and we based on the specific circumstances of corrosion on the mechanical seal made the following adjustments: the media side stationary ring with Teflon rings or rubber ring temperature corrosion in the atmosphere quiet side always use rubber ring ring ; ring PTFE seals are generally used , the effect is more ideal .
Bushings eliminate fretting , except try to use the sleeve surface hardness, good corrosion resistance, and maternal affinity, high surface finish of better spraying spraying materials and processes , but also pay attention when installing bushings wear, timely replacement of bushings, new security seals, in many ways to ensure sealing reliability.
2013年10月26日星期六
Pump mechanical seal failure analysis
Mechanical seal means two sealing elements perpendicular to the axis of the smooth and flat surface bonded to each other and constituting the sealing relative to the rotation of the device. It usually consists of stationary ring , ring , spring loading device ( including the thrust ring , spring , spring seat , fixing screws , drive pin ) , the auxiliary ring ( ring ring seals and static seals ) and other components . Anti-rotation pin fixed to the gland to prevent static ring rotation.
From a structural point of view, the mechanical seal is easy to leak mainly axial seal , change the seal easily leaks . Because of mechanical seal has sealing performance , reliable, leak less , long life, low power consumption , does not require frequent maintenance, etc. , and can meet the production automation and high temperature , releasable cable ties low temperature, high pressure, high vacuum , high speed, a variety of explosive , corrosive and corrosive media sealing requirements , thus to obtain more rapidly than other sealing the development and promotion of more and more alternative packing seal and other seals .
Early failure of the mechanical seal now common phenomenon , causes and remedies described below:
A new face early wear and tear causes and solutions
Mechanical seal face common cause early wear and tear are the following .
1.1 motorized ring and stationary ring material selection is appropriate
By the ring and static friction ring is composed of the most important parts of the mechanical seal . Seal life and work quality ( leakage index ) are and it has a direct relationship .
Mechanical seal friction material according to the nature of the pump working medium , working pressure , temperature, rotation speed and other factors to choose, especially for old products on mechanical seal or packing seal retrofit transformation of the original mechanical seals , mechanical seals rational choice material is very important. When the mechanical seal in a corrosive medium, it is subjected to a chemical and galvanic corrosion , particularly in the friction surface , the corrosion rate is great , it is just because the end surface of the corrosion product is generated ( to reduce the corrosion rate ) was friction cause damage .bolt security seals This generated by corrosion-resistant surface to rub off , periodic cycles of more than, often referred to abrasion phenomenon . The abrasion rate of about no friction surface corrosion rate of 10 to 50 times . Therefore, the friction should choose both corrosion resistance and good wear resistance of materials . Generally , graphite impregnated with phenolic resin acid not alkali , acid and also alkali impregnated furan resin , epoxy resin impregnated alkali resistance , impregnated with PTFE resin and ceramic capability corrosive media .
From a structural point of view, the mechanical seal is easy to leak mainly axial seal , change the seal easily leaks . Because of mechanical seal has sealing performance , reliable, leak less , long life, low power consumption , does not require frequent maintenance, etc. , and can meet the production automation and high temperature , releasable cable ties low temperature, high pressure, high vacuum , high speed, a variety of explosive , corrosive and corrosive media sealing requirements , thus to obtain more rapidly than other sealing the development and promotion of more and more alternative packing seal and other seals .
Early failure of the mechanical seal now common phenomenon , causes and remedies described below:
A new face early wear and tear causes and solutions
Mechanical seal face common cause early wear and tear are the following .
1.1 motorized ring and stationary ring material selection is appropriate
By the ring and static friction ring is composed of the most important parts of the mechanical seal . Seal life and work quality ( leakage index ) are and it has a direct relationship .
Mechanical seal friction material according to the nature of the pump working medium , working pressure , temperature, rotation speed and other factors to choose, especially for old products on mechanical seal or packing seal retrofit transformation of the original mechanical seals , mechanical seals rational choice material is very important. When the mechanical seal in a corrosive medium, it is subjected to a chemical and galvanic corrosion , particularly in the friction surface , the corrosion rate is great , it is just because the end surface of the corrosion product is generated ( to reduce the corrosion rate ) was friction cause damage .bolt security seals This generated by corrosion-resistant surface to rub off , periodic cycles of more than, often referred to abrasion phenomenon . The abrasion rate of about no friction surface corrosion rate of 10 to 50 times . Therefore, the friction should choose both corrosion resistance and good wear resistance of materials . Generally , graphite impregnated with phenolic resin acid not alkali , acid and also alkali impregnated furan resin , epoxy resin impregnated alkali resistance , impregnated with PTFE resin and ceramic capability corrosive media .
New seal ring fragmentation causes and prevention measures
mechanical security seals seal ring fragmentation is a common phenomenon of early failure . Graphite stationary ring main is broken off , ceramic , tungsten carbide ring is mainly Seals cracks and deformation . Graphite ring broken off , a serious leak sealing , sealing medium pressure greater than the pressure can not be guaranteed . Although ring crack , causing leakage increased, but in most cases, but also to maintain operation . Resulting graphite ring broken off for many reasons , mainly the following .
( 1 ) Rubber seals or PTFE V-ring and graphite ring and stationary ring seat fit too tight , graphite by squeezing , under the dynamic fragmentation .
( 2 ) Install the seal chamber and pump in shock when heavy or pump seal chamber heavily skewed .
( 3 ) the swing axis and the string exceeds the specified value.
( 4 ) seal water interruption friction dry friction, high temperature , sealing ring thermal cracking , but suddenly sent to seal water , violent contraction of the seal ring fragmentation .
Ring crack main reasons are:
( 1 ) carbide ring , there is a greater stress on moving ring operation, in force , under the combined effects of internal forces cracks . These cracks are diverging radially dense fine cracks.
( 2 ) Temperature: non-metallic materials for the seal ring ( such as ceramic , WC), due to thermal conduction is not good , the ring is very uneven temperature distribution , even in normal conditions, the temperature may reach several Baidu , the temperature difference due to the presence and, thus, thermal stress caused by thermal deformation . When the thermal stress reaches a certain level , resulting in stress exceeds the ultimate strength of the material . At this time, the sealing ring on brittle materials tend to produce surface cracking , thereby enabling the sealing surface of the friction and wear and tear and failure. Due to thermal deformation of the sealing surface will fit clearance distortion, thus increasing the leakage .
Ring face with carbide , due to the thermal expansion coefficients of these materials are small , and the substrate materials, the thermal expansion coefficient difference between the larger ( stainless steel carbide thermal expansion coefficient than 3 to 4 times ) , so when the sealing temperature l exceeds a certain value , it will cause surfacing carbide seal ring deformation or cracks.
Solving dynamic and static bad fragmentation and deformation effective measures , in addition to strictly control the quality of spare parts processing , careful installation and maintenance , enhance operational management , the guarantee can be fully cable seals face lubrication and cooling are important measures. However, in practice, not any time to ensure adequate lubrication and cooling , seal water pressure fluctuations , disruption and misuse of workers , will cause the seal to lose sufficient lubrication and cooling.
( 1 ) Rubber seals or PTFE V-ring and graphite ring and stationary ring seat fit too tight , graphite by squeezing , under the dynamic fragmentation .
( 2 ) Install the seal chamber and pump in shock when heavy or pump seal chamber heavily skewed .
( 3 ) the swing axis and the string exceeds the specified value.
( 4 ) seal water interruption friction dry friction, high temperature , sealing ring thermal cracking , but suddenly sent to seal water , violent contraction of the seal ring fragmentation .
Ring crack main reasons are:
( 1 ) carbide ring , there is a greater stress on moving ring operation, in force , under the combined effects of internal forces cracks . These cracks are diverging radially dense fine cracks.
( 2 ) Temperature: non-metallic materials for the seal ring ( such as ceramic , WC), due to thermal conduction is not good , the ring is very uneven temperature distribution , even in normal conditions, the temperature may reach several Baidu , the temperature difference due to the presence and, thus, thermal stress caused by thermal deformation . When the thermal stress reaches a certain level , resulting in stress exceeds the ultimate strength of the material . At this time, the sealing ring on brittle materials tend to produce surface cracking , thereby enabling the sealing surface of the friction and wear and tear and failure. Due to thermal deformation of the sealing surface will fit clearance distortion, thus increasing the leakage .
Ring face with carbide , due to the thermal expansion coefficients of these materials are small , and the substrate materials, the thermal expansion coefficient difference between the larger ( stainless steel carbide thermal expansion coefficient than 3 to 4 times ) , so when the sealing temperature l exceeds a certain value , it will cause surfacing carbide seal ring deformation or cracks.
Solving dynamic and static bad fragmentation and deformation effective measures , in addition to strictly control the quality of spare parts processing , careful installation and maintenance , enhance operational management , the guarantee can be fully cable seals face lubrication and cooling are important measures. However, in practice, not any time to ensure adequate lubrication and cooling , seal water pressure fluctuations , disruption and misuse of workers , will cause the seal to lose sufficient lubrication and cooling.
2013年10月24日星期四
How to choose the right repair seals
Notice for users in the purchase of maintenance repair seals , most users will be according to the sample size and color to buy, this will only increase the difficulty of purchasing , but not necessarily be able to select the appropriate product. The following procedures are recommended to improve the accuracy of purchase seals :
1 the direction of movement - first determine the location of the sealing member movement direction , such reciprocating , rotary ,ss cable ties screw or fixed .
2 Sealed focus - such as deciding the point of activity in the inner diameter of the rod seal or activity point is at the outer diameter of the piston seal.
3 Temperature Class - Instructions for use machinery from the factory to inspect or assess the actual working environment temperature, determine the required use of materials . For a description of the temperature level of production users can refer to the following precautions .
4 pressure levels - from factory machinery access to the relevant data for use , or by observing the original seals and structural inference softness working pressure rating, a description of the relevant pressure level production users can refer to the following precautions .
5 size - most users will by used to buy old samples , but seals in use for some time, will be the temperature,colored cable ties pressure and wear and tear and other factors significantly affect its original size, press the select sample only as a reference , a better approach is to measure the location of the metal seal tank size , accuracy will be higher .
1 the direction of movement - first determine the location of the sealing member movement direction , such reciprocating , rotary ,ss cable ties screw or fixed .
2 Sealed focus - such as deciding the point of activity in the inner diameter of the rod seal or activity point is at the outer diameter of the piston seal.
3 Temperature Class - Instructions for use machinery from the factory to inspect or assess the actual working environment temperature, determine the required use of materials . For a description of the temperature level of production users can refer to the following precautions .
4 pressure levels - from factory machinery access to the relevant data for use , or by observing the original seals and structural inference softness working pressure rating, a description of the relevant pressure level production users can refer to the following precautions .
5 size - most users will by used to buy old samples , but seals in use for some time, will be the temperature,colored cable ties pressure and wear and tear and other factors significantly affect its original size, press the select sample only as a reference , a better approach is to measure the location of the metal seal tank size , accuracy will be higher .
The main characteristics of polysulfide sealant
Because liquid polysulfide polymer main chain containing -ss- bond , and is saturated , so the sealant made with unique properties : oil, water , solvent resistance to atmospheric aging , resistance to radiation , low temperature , good song , excellent air tightness . Can be used for construction projects , large reservoirs, diversion works , sewage treatment , bolt security seals roads, bridges , doors, windows and other joints , settlement is sealed.
l, adhesion : polysulfide sealant for cement , steel, glass, wood , natural stone , etc. have good adhesion. General building and water conservancy projects on the appropriate use of low modulus, high elongation polysulfide sealant , its bond strength ≥ 0.2Mpa, Elongation ≥ 300%.
2, the water resistance : polysulfide sealant for water, tap water, distilled water, the role of stability , compared to seawater ( salt ) the minimum change in weight .
3 , acid and alkaline able to: polysulfide sealant resistant to strong acids, alkalis . However, the dilute mineral acid, vehicle seals alkali and various salts , or stable .
4 , heat aging properties : polysulfide sealant heat aging performance very good, long-term in a 40 ℃ ~ 120 ℃ working conditions .
l, adhesion : polysulfide sealant for cement , steel, glass, wood , natural stone , etc. have good adhesion. General building and water conservancy projects on the appropriate use of low modulus, high elongation polysulfide sealant , its bond strength ≥ 0.2Mpa, Elongation ≥ 300%.
2, the water resistance : polysulfide sealant for water, tap water, distilled water, the role of stability , compared to seawater ( salt ) the minimum change in weight .
3 , acid and alkaline able to: polysulfide sealant resistant to strong acids, alkalis . However, the dilute mineral acid, vehicle seals alkali and various salts , or stable .
4 , heat aging properties : polysulfide sealant heat aging performance very good, long-term in a 40 ℃ ~ 120 ℃ working conditions .
2013年10月23日星期三
Selection of gasket
Widely used in the gasket pipes, pressure vessels and various body joint surface static seal . There are non-metallic gaskets gaskets , non-metallic gaskets and metal combination and metal gasket three categories. The commonly used materials are rubber, leather , asbestos nylon zip ties, cork , PTFE , steel, iron, copper and stainless steel .
Gasket leaks in three forms : the interface leakage, infiltration leaks and destructive leak. Where previously the two as the main form .
Gasket selection :
Gasket selection principle is that, for less demanding situations, can be empirically selected sub- city again when replaced. But for those demanding applications such as explosive, toxic and combustible gases and highly corrosive liquids equipment, reaction tank and pipeline systems, etc. , should be based on operating pressure , operating temperature, sealed.
Flange surface roughness . The surface roughness of the sealing flange great effect , especially when using non- flexible gasket , the sealing surface roughness is caused by leakage of a large value of the main. For example , turning the blade flange is a spiral line pattern , using the metal gasket , if the roughness is large, it can not block the knife profile gasket is formed of spiral grooves which , under pressure , the media will along this trench leaked . Soft gasket to the flange surface finish is required is much lower, this is because it is easily deformed , fixed length plastic strap seal to block the machining tool pattern, thereby preventing leakage. Right soft gasket and flange surface is too smooth detriment .
Gasket leaks in three forms : the interface leakage, infiltration leaks and destructive leak. Where previously the two as the main form .
Gasket selection :
Gasket selection principle is that, for less demanding situations, can be empirically selected sub- city again when replaced. But for those demanding applications such as explosive, toxic and combustible gases and highly corrosive liquids equipment, reaction tank and pipeline systems, etc. , should be based on operating pressure , operating temperature, sealed.
Flange surface roughness . The surface roughness of the sealing flange great effect , especially when using non- flexible gasket , the sealing surface roughness is caused by leakage of a large value of the main. For example , turning the blade flange is a spiral line pattern , using the metal gasket , if the roughness is large, it can not block the knife profile gasket is formed of spiral grooves which , under pressure , the media will along this trench leaked . Soft gasket to the flange surface finish is required is much lower, this is because it is easily deformed , fixed length plastic strap seal to block the machining tool pattern, thereby preventing leakage. Right soft gasket and flange surface is too smooth detriment .
Heat pump mechanical seal Precautions
Heat pump according to the conditions of use of the different installation of different forms of mechanical seals , such as the built-in single-ended flat horizontal and non- balanced ,high security cable seals double-end balanced and unbalanced type , externally mounted mechanical seals , etc. Therefore , according to the choice of seals in different forms, its using methods and precautions are also different, generally have the following specific conditions :
1, the general mechanical seal suitable for cleaning medium without suspended particles , on the newly installed piping system should be carefully cleaned reservoir together to prevent solid impurities into the mechanical seal faces .
2, in the crystallization medium using mechanical seals , attention should be cleaned regularly , before the restart after stopping to get crystal mechanical seal clean .
3 , the mechanical seal should be carefully disassemble , prohibited by hand cone, iron and other percussion . Demolition should be clear dirt.
4 , strict inspection ring and the stationary ring for face grinding , does not allow any minor scratches, Pengpo other defects.
5 , the right to adjust the amount of compression springs , making it an appropriate degree of tightness to avoid excessive wear or leakage.
6, there is an external mechanical seal flush , start should be preceded by open cavity filled with fluid sealing liquid is sealed ,adjustable length plastic seals stopping when the first stop the pump, close the seal flush fluid.
1, the general mechanical seal suitable for cleaning medium without suspended particles , on the newly installed piping system should be carefully cleaned reservoir together to prevent solid impurities into the mechanical seal faces .
2, in the crystallization medium using mechanical seals , attention should be cleaned regularly , before the restart after stopping to get crystal mechanical seal clean .
3 , the mechanical seal should be carefully disassemble , prohibited by hand cone, iron and other percussion . Demolition should be clear dirt.
4 , strict inspection ring and the stationary ring for face grinding , does not allow any minor scratches, Pengpo other defects.
5 , the right to adjust the amount of compression springs , making it an appropriate degree of tightness to avoid excessive wear or leakage.
6, there is an external mechanical seal flush , start should be preceded by open cavity filled with fluid sealing liquid is sealed ,adjustable length plastic seals stopping when the first stop the pump, close the seal flush fluid.
2013年10月22日星期二
Conical shaft for the mechanical seal of the swing
Shaft swings may occur depending on the maximum pump heads ( the bottom one ) fluorine resin bearing radial clearance . According to the manufacturer 's standard , 9LDTN type condensate pump bearings allow maximum use of fluorine resin gap 0.4 mm, taking into account the fluorine resin bearing wear will not damage after mechanical seal , based on past experience overhaul , whichever heads fluorine resin bearing radial clearance to 2 mm. Principles calculations based on similar triangles , the mechanical seal shaft runout limit value of 0.24 mm, and then consider rolling under its own motor radial clearance is set to 0.1mm ( for 6226 bearing is damaged in terms of the gap ) , then mechanical shaft seals can get maximum runout of 0.34 mm. The selected mechanical seal allows runout of 0.5 ~ 0.7 mm, it will not damage the shaft for mechanical seal conical swing .
Transformation is due to the choice of cartridge single mechanical seal , installation is relatively simple and does not require any transformation of the pump , mechanical seal less work . However, in the transformation process involves the following considerations :
a) Check the condensate pump original packing sleeve outer periphery of ovality , elliptical too large to be replaced. Because mechanical seal sleeve must set this sleeve , with the Department by its O-ring indicative seal, sleeve oval spend much effect on the O-ring and sleeve contacts , causing leaks here .
b) packing sleeve and the shaft seal must be reliable without leakage, if packing between the sleeve and the shaft seal leakage , condensation will also affect water quality and vacuum unit .
c) the original packing chamber condensate pump outer face flat on the lathe processing needs . In order to ensure the mechanical seal stationary ring gland with a combination of good surface contact , it is best to fill up the cavity outer face flange portion for turning .
d) Install the mechanical seal , in a still sealed position using a good quality sealant to prevent leakage.
e) mechanical seal is in place, the pump and the motor must be in good and installed on the coupling after a fixed stationary ring and ring gland , and finally will be positioned to take the card to open . Otherwise , couplings and joints for adjusting the pendulum will cause partial radial and axial elevation will not only affect the mechanical seal static ring sealing surface contact , but also changes the mechanical seal tight static ring contact force, contact tightening force burned mechanical adjustable length seal over the General Assembly .
f) mechanical seal return pipe must be connected back to the pump inlet . Because the upper guide bearing a relief bore seal leakage , it serves to ensure the mechanical seal chamber pressure of not more than 490 kPa in effect, while the return pipe connected to a lower pressure , they may form a flow in order to promptly the movement of the mechanical seal sealing surface due to friction heat away .
Transformation is due to the choice of cartridge single mechanical seal , installation is relatively simple and does not require any transformation of the pump , mechanical seal less work . However, in the transformation process involves the following considerations :
a) Check the condensate pump original packing sleeve outer periphery of ovality , elliptical too large to be replaced. Because mechanical seal sleeve must set this sleeve , with the Department by its O-ring indicative seal, sleeve oval spend much effect on the O-ring and sleeve contacts , causing leaks here .
b) packing sleeve and the shaft seal must be reliable without leakage, if packing between the sleeve and the shaft seal leakage , condensation will also affect water quality and vacuum unit .
c) the original packing chamber condensate pump outer face flat on the lathe processing needs . In order to ensure the mechanical seal stationary ring gland with a combination of good surface contact , it is best to fill up the cavity outer face flange portion for turning .
d) Install the mechanical seal , in a still sealed position using a good quality sealant to prevent leakage.
e) mechanical seal is in place, the pump and the motor must be in good and installed on the coupling after a fixed stationary ring and ring gland , and finally will be positioned to take the card to open . Otherwise , couplings and joints for adjusting the pendulum will cause partial radial and axial elevation will not only affect the mechanical seal static ring sealing surface contact , but also changes the mechanical seal tight static ring contact force, contact tightening force burned mechanical adjustable length seal over the General Assembly .
f) mechanical seal return pipe must be connected back to the pump inlet . Because the upper guide bearing a relief bore seal leakage , it serves to ensure the mechanical seal chamber pressure of not more than 490 kPa in effect, while the return pipe connected to a lower pressure , they may form a flow in order to promptly the movement of the mechanical seal sealing surface due to friction heat away .
Measures to eliminate shaft deflection is too large
This phenomenon exists mostly horizontal multistage centrifugal pump , in the design of the following measures:
( A ) to reduce the distance between the ends of the bearing . Pump impeller stages not too much higher in the pump total head case , try to improve each impeller head, reducing progression .
( 2 ) increasing the diameter of the shaft . In the design of the shaft diameter , do not simply transfer power only to consider the size , and to consider the mechanical seal,tamper evident tape shaft deflection , starting methods and related inertia load , radial force and other factors. Many designers do not fully understand it.
( 3) improve the level of the shaft material .
( 4 ) shaft before installation on the shaft deflection test to be checked .
4 increase in auxiliary flushing system
When conditions permit , try to flush the system design assistance . General requirements for flushing pressure is higher than the seal chamber pressure 0.107 ~ 0.11 MPa, if the transmission medium is easily vaporized , the vapor pressure should be higher than 0.1175 ~ 0.12 MPa. Seal chamber pressure pump according to the structure of each type, and other factors to calculate the system pressure . Seal chamber pressure is high or when the pressure is almost close to the seal using the highest limit, also cited by the liquid seal chamber to the low pressure area , so that the liquid flow to seal away frictional heat . Recommended flushing volume as shown in Table 1 .
Pump mechanical seal table
According to the operating conditions of each pump , a reasonable allocation of piping and accessories. Such as coolers, plate , filters , valves, flow indicators , pressure gauge and temperature. Actually seal the reliability and life depends largely on the nylon cable tie support system configuration.
( A ) to reduce the distance between the ends of the bearing . Pump impeller stages not too much higher in the pump total head case , try to improve each impeller head, reducing progression .
( 2 ) increasing the diameter of the shaft . In the design of the shaft diameter , do not simply transfer power only to consider the size , and to consider the mechanical seal,tamper evident tape shaft deflection , starting methods and related inertia load , radial force and other factors. Many designers do not fully understand it.
( 3) improve the level of the shaft material .
( 4 ) shaft before installation on the shaft deflection test to be checked .
4 increase in auxiliary flushing system
When conditions permit , try to flush the system design assistance . General requirements for flushing pressure is higher than the seal chamber pressure 0.107 ~ 0.11 MPa, if the transmission medium is easily vaporized , the vapor pressure should be higher than 0.1175 ~ 0.12 MPa. Seal chamber pressure pump according to the structure of each type, and other factors to calculate the system pressure . Seal chamber pressure is high or when the pressure is almost close to the seal using the highest limit, also cited by the liquid seal chamber to the low pressure area , so that the liquid flow to seal away frictional heat . Recommended flushing volume as shown in Table 1 .
Pump mechanical seal table
According to the operating conditions of each pump , a reasonable allocation of piping and accessories. Such as coolers, plate , filters , valves, flow indicators , pressure gauge and temperature. Actually seal the reliability and life depends largely on the nylon cable tie support system configuration.
2013年10月11日星期五
Cycloid gear pump industry applications extended
Because nothing like cycloid gear involute gears meshing in the center distance separability , tooth profile curve equation is complex and engaging ordinary cycloid gear pump is a multi- point contact . Gang Here, cycloid gear machining high precision , small processing errors might prevent the assembly, or uneven loads .security tie Prior to the 1980s of last century by means of design calculations and processing technical limitations , cycloid gear pump application subject to certain restrictions. With the increased level of processing technology , especially the development of numerical control technology , cycloid gear machining accuracy gradually improved , the cost becomes lower , cycloid pump renewed attention .
Its application range with gradually expanded from general industrial extended to the field of micro-mechanical hydraulic systems and bio- engineering . With more teeth difference cycloid gear pump and the emergence of modern design and manufacturing technology development , research and cycloid gear pump by domestic and foreign scholars and producers attention. Recently, there are many foreign companies producing such a gear pump . It is understood that a large number of imports from abroad, air compressors, chillers, oxygen compressors, expanders , and a large number of chemical raw material conveyors often appear on the cycloid gear pump , especially in the chemical industry for delivering high-viscosity liquids on the device .trailer seals China also has many companies began producing teeth difference cycloid pump , but all in imitation of similar products abroad , mainly in order to meet the need for equipment maintenance .
Its application range with gradually expanded from general industrial extended to the field of micro-mechanical hydraulic systems and bio- engineering . With more teeth difference cycloid gear pump and the emergence of modern design and manufacturing technology development , research and cycloid gear pump by domestic and foreign scholars and producers attention. Recently, there are many foreign companies producing such a gear pump . It is understood that a large number of imports from abroad, air compressors, chillers, oxygen compressors, expanders , and a large number of chemical raw material conveyors often appear on the cycloid gear pump , especially in the chemical industry for delivering high-viscosity liquids on the device .trailer seals China also has many companies began producing teeth difference cycloid pump , but all in imitation of similar products abroad , mainly in order to meet the need for equipment maintenance .
Gear pump hydraulic system development
In order to adapt hydraulic system is toward fast response , small size, low noise direction, gear pumps in addition to actively take measures to maintain its low-pressure dosing system , lubrication system dominance , but still need the following directions:
( 1 ) low flow pulsation : flow pulsation will cause pressure fluctuations , causing the system to generate vibration and noise, which is associated with the requirements of modern hydraulic systems are inconsistent . Reduce flow pulsation method , in addition to the previously described measures, Saikawa complex multi- gear pump is a trend.
( 2 ) high-voltage technology : higher pressure is required by the system , but also gear pumps and piston pumps, vane pumps competition must be addressed . The high pressure gear pump of the work has made great progress , but by its own structural limitations , in order to further improve the working pressure is very difficult to be developed a new structure of the gear pump . In this regard, by a plurality of composite gear pump gear will have a great advantage, the country has many researchers has conducted some research, and achieved remarkable results pull tight plastic seals.
( 3 ) Low noise: abroad have long been "quiet" pump said. As people's awareness of environmental protection , the gear pump noise requirements have become more stringent. Gear pump noise is mainly composed of two parts , part of the process of meshing gear mechanical noise generated in the other part of the trapped oil hydraulic pressure generated by the impact of noise. The former gear precision machining and installation , while the latter mainly depends on the thoroughness of the pump unloading . For external gear pump , to achieve complete unloading is very difficult, thus further reducing pump noise subject to certain restrictions . In this regard, due to internal gear pump has a smooth , non- trapped oil phenomenon , low noise characteristics and attracted universal attention , especially linear conjugate tooth profile of the internal gear pump because of its smooth operation, low noise, and much favor , is becoming the focus of research .
( 4 ) Variable Displacement: gear pump displacement can not be adjusted , limiting its scope to use the same . In order to change the gear pump displacement , domestic and foreign scholars have done a lot of research work, and made a lot of research results. For variable displacement gear pump has a lot of aspects of the patent , but really very little can be converted into products . Balanced compound gear internal gear pump can be adjusted by changing the speed of the pump displacement meters , but the specific methods and structures to be studied further tamper seal.
( 5 ) Large displacement : For some systems require fast moving rice , said large displacement is required. But conventional gear pump displacement increased by many factors. This regard , balanced compound gear pump has significant advantages , such as a table three composite idler gear pump displacement equivalent to 6 units with a single pump displacement dimensions .
( 1 ) low flow pulsation : flow pulsation will cause pressure fluctuations , causing the system to generate vibration and noise, which is associated with the requirements of modern hydraulic systems are inconsistent . Reduce flow pulsation method , in addition to the previously described measures, Saikawa complex multi- gear pump is a trend.
( 2 ) high-voltage technology : higher pressure is required by the system , but also gear pumps and piston pumps, vane pumps competition must be addressed . The high pressure gear pump of the work has made great progress , but by its own structural limitations , in order to further improve the working pressure is very difficult to be developed a new structure of the gear pump . In this regard, by a plurality of composite gear pump gear will have a great advantage, the country has many researchers has conducted some research, and achieved remarkable results pull tight plastic seals.
( 3 ) Low noise: abroad have long been "quiet" pump said. As people's awareness of environmental protection , the gear pump noise requirements have become more stringent. Gear pump noise is mainly composed of two parts , part of the process of meshing gear mechanical noise generated in the other part of the trapped oil hydraulic pressure generated by the impact of noise. The former gear precision machining and installation , while the latter mainly depends on the thoroughness of the pump unloading . For external gear pump , to achieve complete unloading is very difficult, thus further reducing pump noise subject to certain restrictions . In this regard, due to internal gear pump has a smooth , non- trapped oil phenomenon , low noise characteristics and attracted universal attention , especially linear conjugate tooth profile of the internal gear pump because of its smooth operation, low noise, and much favor , is becoming the focus of research .
( 4 ) Variable Displacement: gear pump displacement can not be adjusted , limiting its scope to use the same . In order to change the gear pump displacement , domestic and foreign scholars have done a lot of research work, and made a lot of research results. For variable displacement gear pump has a lot of aspects of the patent , but really very little can be converted into products . Balanced compound gear internal gear pump can be adjusted by changing the speed of the pump displacement meters , but the specific methods and structures to be studied further tamper seal.
( 5 ) Large displacement : For some systems require fast moving rice , said large displacement is required. But conventional gear pump displacement increased by many factors. This regard , balanced compound gear pump has significant advantages , such as a table three composite idler gear pump displacement equivalent to 6 units with a single pump displacement dimensions .
2013年10月9日星期三
Wear of the pump bearings and seals resistant to solutions
( A ) problem : support bearing severe wear . Try a number of different plant materials, such as carbon , graphite, Teflon ® material with fillers , trying to find a suitable solution to the problem of wear and misalignment , all materials 2-3 months to be scrapped . Wherein the polytetrafluoroethylene material products due to wear so that the shaft wear, have a great leak , causing mechanical seal failure.
Workaround: polyimide carbon fiber composite materials instead of the original use of a filler PTFE bearings.
Results: polyimide carbon fiber composite material support bearings installed, has been successfully operating for more than 13 months , after using the first eight months , the central part of the agitator is removed temporarily use other equipment , then , the staff detected stirrer bearings, found on each side leakage rate is less than 0.005 per inch , then the average failure interval time increased by 300% to 400%.
(B ) the problem : the axis deviation caused by high vibration and shorten the life of the mechanical security seals, while generating the noise .
Workaround: polyimide carbon fiber composite material with stainless steel impeller mouth ring pump housing orifice ring ; using our materials throat bushings instead of the original graphite bushings.
Result: reduced vibration amplitude , thus extending the service life of the seal and bearing life , and enhance the free operation of the pump . Many pumps are in use as a filler in packing , packing main role is to prevent leaks, but also play a role in the bearing , stable axis . At present, many pumps have packing to mechanical seals, mechanical seals with the changes did not affect the bearing , while the axis deviation ( high vibration and associated impacts ) has become a problem .
Polyimide carbon fiber composite materials to improve pump , successfully resolved the customer's problem , the following main points:
A ) polyimide carbon fiber composite material is a non- metal wear , do not bite material . This allows the running clearance out ( API provides only half the interstitial metal material ), the smaller the gap can stabilize shaft bush , the smaller the gap can further limit the leakage orifice ring and leak rate.
2 ) Polyimide carbon fiber composite material is a high strength , high performance thermoplastic material .pull tight seal It is easy to injection molding, can absorb vibration and shock , while the metal is being replaced will cause vibration and shaft wear .
Parts : Equipped with a removable Teflon seal and bearing sleeve
Workaround: polyimide carbon fiber composite materials instead of the original use of a filler PTFE bearings.
Results: polyimide carbon fiber composite material support bearings installed, has been successfully operating for more than 13 months , after using the first eight months , the central part of the agitator is removed temporarily use other equipment , then , the staff detected stirrer bearings, found on each side leakage rate is less than 0.005 per inch , then the average failure interval time increased by 300% to 400%.
(B ) the problem : the axis deviation caused by high vibration and shorten the life of the mechanical security seals, while generating the noise .
Workaround: polyimide carbon fiber composite material with stainless steel impeller mouth ring pump housing orifice ring ; using our materials throat bushings instead of the original graphite bushings.
Result: reduced vibration amplitude , thus extending the service life of the seal and bearing life , and enhance the free operation of the pump . Many pumps are in use as a filler in packing , packing main role is to prevent leaks, but also play a role in the bearing , stable axis . At present, many pumps have packing to mechanical seals, mechanical seals with the changes did not affect the bearing , while the axis deviation ( high vibration and associated impacts ) has become a problem .
Polyimide carbon fiber composite materials to improve pump , successfully resolved the customer's problem , the following main points:
A ) polyimide carbon fiber composite material is a non- metal wear , do not bite material . This allows the running clearance out ( API provides only half the interstitial metal material ), the smaller the gap can stabilize shaft bush , the smaller the gap can further limit the leakage orifice ring and leak rate.
2 ) Polyimide carbon fiber composite material is a high strength , high performance thermoplastic material .pull tight seal It is easy to injection molding, can absorb vibration and shock , while the metal is being replaced will cause vibration and shaft wear .
Parts : Equipped with a removable Teflon seal and bearing sleeve
Characteristics of Compound Gear Pump
A ) compound gear pump flow characteristics ;
2 ) Compound Gear Pump Optimization Method ;
3 ) radial force balance methods and measures .seal cable Compound gear pump flow characteristics of the parameters involved in the calculation more complicated calculation , must resort to computer-aided design methods to achieve.
( 6 ) helical gear pumps helical gear pump research study is currently the focus of attention of researchers in domestic issues , Ganxue Hui , Zhao Liang and so on helical gear pump flow characteristics , the leakage flow characteristics , flow pulsation characteristics a study of helical gear pump research has laid a theoretical foundation.
( 7 ) gear pump gear pump noise noise control technology is engaged by the flow pulsation and shock caused by the control flow pulsation and noise from the lower tooth profile to start asking the relative sliding velocity .
( 8 ) Method of a variable gear pump gear pump because the engagement of the gear pump flow characteristic adjustment has been a problem , only up to consider the structural solution , there is no effective solution.
( 9 ) means of high-pressure gear pump gear pump working pressure increase is a development direction of the gear pump , the pressure increase caused by the question :
( 1 ) bearing life is shortened, shortening the life of the pump :
( 2 ) pump leak intensifies, the volumetric efficiency decreases.
Produce these two issues fundamental reason lies in the role of the unbalanced gear radial hydraulic pressure ,padlock seal and the pressure is higher, the greater the radial hydraulic pressure .
( 10 ) gear pump life and its influencing factors . Meshing gear pump unbalanced radial force is affecting the life of the main factors gear pump . Hydrostatic bearings can be used , reducing the radial force methods to improve the life of the gear pump , while reducing the radial force of the most effective way is to use more complex gear pump gear .
2 ) Compound Gear Pump Optimization Method ;
3 ) radial force balance methods and measures .seal cable Compound gear pump flow characteristics of the parameters involved in the calculation more complicated calculation , must resort to computer-aided design methods to achieve.
( 6 ) helical gear pumps helical gear pump research study is currently the focus of attention of researchers in domestic issues , Ganxue Hui , Zhao Liang and so on helical gear pump flow characteristics , the leakage flow characteristics , flow pulsation characteristics a study of helical gear pump research has laid a theoretical foundation.
( 7 ) gear pump gear pump noise noise control technology is engaged by the flow pulsation and shock caused by the control flow pulsation and noise from the lower tooth profile to start asking the relative sliding velocity .
( 8 ) Method of a variable gear pump gear pump because the engagement of the gear pump flow characteristic adjustment has been a problem , only up to consider the structural solution , there is no effective solution.
( 9 ) means of high-pressure gear pump gear pump working pressure increase is a development direction of the gear pump , the pressure increase caused by the question :
( 1 ) bearing life is shortened, shortening the life of the pump :
( 2 ) pump leak intensifies, the volumetric efficiency decreases.
Produce these two issues fundamental reason lies in the role of the unbalanced gear radial hydraulic pressure ,padlock seal and the pressure is higher, the greater the radial hydraulic pressure .
( 10 ) gear pump life and its influencing factors . Meshing gear pump unbalanced radial force is affecting the life of the main factors gear pump . Hydrostatic bearings can be used , reducing the radial force methods to improve the life of the gear pump , while reducing the radial force of the most effective way is to use more complex gear pump gear .
2013年10月8日星期二
Beverage bottle child may drink into the container sealed proposal
News Playback frequency exposure safety issues bottled beverages
As temperatures gradually warming , bottled drinks ushered in the year of the sales season. At the same time , some information about the safety of bottled beverages reports but can often be seen .
Ms. Wang Hefei Parkson supermarket bought in Jasmine Tea Master of bottled beverages. Open only to find that the cap wall covered with black mold substances . After Ms. Wang found a manufacturer, factory explanation is " previously encountered such a problem may be caused by moisture on the supermarket warehouse ."
In recent years , with regard to beverage bottle moldy , breeding eggs , frequent reports of excessive bacteria . These problems involve many well-known brands , showing not the case. The brand is also more for such quality issues attributed to warehousing, transportation and other circulation . Well, we almost daily consumption of bottled drinks, they are not fully sealed bottle in the end it ? Please enter the living laboratory period , the facts to give you the answer.
Sample: 4 bottles of mineral water , label 1,2,3,4 , 1,2 for the same brand of mineral water, which is internally threaded cap double parallel lines, 3,4 for the same brand of mineral water , which internal thread for the screw cap double lines ; gentian violet
Experimental conditions: the fully sealed and then tighten unscrew bottle of mineral water upside down into the gentian violet solution
Experimental Target : gentian violet solution will soak into the inside of the cap
Experimental Procedure
1 The test samples 1,3 unscrew , pour a glass of water , then tighten. Open a bottle of drinking too mimic the situation .
2 gentian violet take about 5 ml was poured into water , the water level height is about 3 cm , can be completely off caps.
3 respectively 1,2 inverted water bottle into the gentian violet solution and let stand for 5 minutes . After removing the bottle with a paper towel and put up dry.
4 Take 3,4 mineral water bottles, repeat step 3.
7 Unscrew guinea pigs 3,4 . Among them, the whole of the 4th sealed bottle caps innermost colored spots appear below the threads 3 , on the outermost whorl coloring water droplets. The 4th bottle mouth with colored spots under the thread , the bottle at no obvious staining . And before the experiment was then tighten the screw to open the 3rd bottle , barrier seals staining slightly above the 4th bottle , the bottle at no obvious staining .
6 Unscrew guinea pigs 1,2 , which is the 2nd bottle sealed inside found no shading . And before the experiment was unscrew and tighten No. 1 bottle , the cap edge coloring inside of the case . Bottles at the bottle and bottle screw were no shading .
5 4 bottles of mineral water to be dried and observed . Bottle of mineral water bottle and cap of about 1 cm were staining .
The 4th bottle caps with colored water droplets inside
Experimental results : closed bottle of mineral water infiltration staining solution is still possible , but it will not penetrate the bottle at .
● Expert Interpretation
Secretary-General of the International Food Packaging Association , professor of environmental experts said threaded portion of beverage bottles only play the role of reinforcement , but not confined, " really play a role in the sealed bottle on a prominent cushion , tightening the cap while pressing close to the bottle, sealing function . "
Introduction, vendors can make through ultrasound and heat shrinkable plastic shrink technology , to enhance or replace the mold bottle seal. But for cost reasons , most companies will not use these technologies , while the domestic beverage bottle hygiene standards at a blank spiral also enable manufacturers failed to give sufficient attention.
Said that as the threaded mouth is not sealed ,security seals in the filling , warehousing, transportation and other aspects of secondary contamination may exist , it is recommended to drink bottled beverages , do not directly touch the bottle mouth . " The use of straw may still exist secondary pollution , advised consumers to pour the beverage in the container and then drink ."
As temperatures gradually warming , bottled drinks ushered in the year of the sales season. At the same time , some information about the safety of bottled beverages reports but can often be seen .
Ms. Wang Hefei Parkson supermarket bought in Jasmine Tea Master of bottled beverages. Open only to find that the cap wall covered with black mold substances . After Ms. Wang found a manufacturer, factory explanation is " previously encountered such a problem may be caused by moisture on the supermarket warehouse ."
In recent years , with regard to beverage bottle moldy , breeding eggs , frequent reports of excessive bacteria . These problems involve many well-known brands , showing not the case. The brand is also more for such quality issues attributed to warehousing, transportation and other circulation . Well, we almost daily consumption of bottled drinks, they are not fully sealed bottle in the end it ? Please enter the living laboratory period , the facts to give you the answer.
Sample: 4 bottles of mineral water , label 1,2,3,4 , 1,2 for the same brand of mineral water, which is internally threaded cap double parallel lines, 3,4 for the same brand of mineral water , which internal thread for the screw cap double lines ; gentian violet
Experimental conditions: the fully sealed and then tighten unscrew bottle of mineral water upside down into the gentian violet solution
Experimental Target : gentian violet solution will soak into the inside of the cap
Experimental Procedure
1 The test samples 1,3 unscrew , pour a glass of water , then tighten. Open a bottle of drinking too mimic the situation .
2 gentian violet take about 5 ml was poured into water , the water level height is about 3 cm , can be completely off caps.
3 respectively 1,2 inverted water bottle into the gentian violet solution and let stand for 5 minutes . After removing the bottle with a paper towel and put up dry.
4 Take 3,4 mineral water bottles, repeat step 3.
7 Unscrew guinea pigs 3,4 . Among them, the whole of the 4th sealed bottle caps innermost colored spots appear below the threads 3 , on the outermost whorl coloring water droplets. The 4th bottle mouth with colored spots under the thread , the bottle at no obvious staining . And before the experiment was then tighten the screw to open the 3rd bottle , barrier seals staining slightly above the 4th bottle , the bottle at no obvious staining .
6 Unscrew guinea pigs 1,2 , which is the 2nd bottle sealed inside found no shading . And before the experiment was unscrew and tighten No. 1 bottle , the cap edge coloring inside of the case . Bottles at the bottle and bottle screw were no shading .
5 4 bottles of mineral water to be dried and observed . Bottle of mineral water bottle and cap of about 1 cm were staining .
The 4th bottle caps with colored water droplets inside
Experimental results : closed bottle of mineral water infiltration staining solution is still possible , but it will not penetrate the bottle at .
● Expert Interpretation
Secretary-General of the International Food Packaging Association , professor of environmental experts said threaded portion of beverage bottles only play the role of reinforcement , but not confined, " really play a role in the sealed bottle on a prominent cushion , tightening the cap while pressing close to the bottle, sealing function . "
Introduction, vendors can make through ultrasound and heat shrinkable plastic shrink technology , to enhance or replace the mold bottle seal. But for cost reasons , most companies will not use these technologies , while the domestic beverage bottle hygiene standards at a blank spiral also enable manufacturers failed to give sufficient attention.
Said that as the threaded mouth is not sealed ,security seals in the filling , warehousing, transportation and other aspects of secondary contamination may exist , it is recommended to drink bottled beverages , do not directly touch the bottle mouth . " The use of straw may still exist secondary pollution , advised consumers to pour the beverage in the container and then drink ."
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