Pump Failure introduce dynamic seal

Core Tip: pump seals are soft packing seals , oil seals , labyrinth seals , spiral seals, dynamic seals and mechanical seals.
Prevent the working medium from leaking out of the pump or to prevent impurities or outside air intrusion into the pump means or measures known internal seal medium to be sealed is generally liquid, gas or dust .
Causing leakage for two main reasons : First, there is a gap sealing surface . Second, the pressure difference on both sides of the sealing parts , to eliminate or reduce any of the factors that can prevent or reduce leakage , to achieve the purpose of sealing . Pressure pump design and the use of pressure is an objective can not be reduced , so that the pump is sealed to the solution to eliminate or reduce the gap between the seal faces . Such a gap includes a gap between the sealing surface and the sealing means within the gap Bunsen .
Mechanical seals
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 seal , 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 numbered seals 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 seals 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.
Oil seals
Self-tight seal is a lip fixed length plastic strap seal , its simple structure , small size , low cost , easy maintenance, resistance torque is small, both to prevent media leaks , but also to prevent external intrusion of dust and other harmful substances , but also to wear have a certain ability to compensate , but the impatience high pressure, it is generally used in low pressure applications. Seal should be installed in the manufacturing precision of h8 ~ h9, the surface roughness of 1.6 ~ 0.8μm and after surface hardening treatment of the shaft . Sealing medium should not contain solid particles and impurities , which will cause rapid wear of the shaft seal and leaving the seal failure.