Impurities are the primary cause leading to damage of sealing elements, which make valves leak by grinding inside sealing elements. So, foreigners proposed that hydraulic elements in appropriate level should match filter in appropriate accuracy. They reckoned that 5μM pump seal match 3/μM filter, which means the service life will be longer than the service life of the 10μM filter.
But when valves used in hydraulic supports, the environment is considerately odiously. On the coal mining working surface, the oil pipe is 100 meters long with more than 4000 joint sockets, while there is no dust equipment in tank. There are many impurities in emulsion, and a lot of coal fines, rock grains and iron filings in the cylinder bottom and valve body.
The seal will soon expire for high liquid flow when liquid enters the body and seat. The practice has shown that it is very difficult to reduce contaminated impurities in liquids in oil-operated support.
Many countries demand anti-contamination when testing valves now. Such as, mix with proper pulverized coal or mechanic impurities in the emulsion. Therefore, the seals are needed, which have new style, good anti-contamination capacity and apply to well condition.
The service life of hydraulic valves is short in hydraulic supports. The solution in other countries is that improving filtering accuracy and emulsion quality, but there is no considerate effect.
Recommendation:
DIN Standard CF8 Gate Valve 4 Inch