Emphasis on the seal check valve

If the valve stem and the valve body bore machining of poor quality, or because of long-term use causes wear leaving the filler stem with the gap increases, the media will lead to leaks from the valve stem, a phenomenon known as the valve "upper seal leak." However, in the fermentation, the valve on the nylon zip ties check is often overlooked.

In the fermentation, because the fermentation process requirements, some of the fluid to the valve is not installed by, as in some of the fermentation tank, the sampling valve is to close the first valve fermenter, the valve in order to be sterilized prior to sampling, valve installation and fermented liquid flow is reversed, so as to install a small sampling valve at the bottom of an additional valve so that the steam flow. The sampling valve on the seal structure sealing requirements are very high, otherwise the fermentation broth may penetrate the sampling valve on the seal structure even leak from the seal structure, resulting in fermentation contamination.

At present, many domestic valve packing for multilayer structure, and the structure has the added filler rigid spacers, an upper sealing ring or a disc spring, thereby improving the sealing force of the self-regulating capacity, improve the sealing performance. In the event of the nylon zip ties leakage, and changes on the domestic valve seal structure is difficult, can be solved by replacing the filler type leak problem. For example, the current expansion of new alternative to conventional PTFE gland packing asbestos and expanded graphite packing, its wear and corrosion resistance, good sealing effect.