Professional maintenance of valves before and after welding operation plays a vital role in serving the production and operation of valves. Correct and orderly maintenance will protect valves, make them function normally and prolong the service life of valves. Valve maintenance seems simple, but it is not. There are often neglected aspects of work.
First, when the valve is injected with fat, the problem of the amount of fat injected is often neglected. After the greasing gun is refueled, the operator chooses the valve and the greasing connection mode, and then carries on the greasing operation. There are two situations: on the one hand, less grease injection and insufficient grease injection, and the sealing surface accelerates wear due to lack of lubricant. On the other hand, excessive fat injection causes waste. Because there is no accurate calculation of different valve sealing capacity according to the type and type of valve. Sealing capacity can be calculated by valve size and type, and then a reasonable amount of grease can be injected.
Secondly, pressure is often neglected in valve grease injection. During the operation of lipid injection, the pressure of lipid injection varies regularly from peak to valley. The pressure is too low, the seal leaks or fails, the pressure is too high, the grease injection mouth is blocked, the inner grease of the seal is hardened or the seal ring is locked with the valve ball and the valve plate. Usually when the pressure of grease injection is too low, the grease injected into the bottom of the valve chamber, usually occurs in small gate valves. The pressure of grease injection is too high, on the one hand, check the grease injection nozzle, such as the identification of the blockage of the grease hole for replacement; on the other hand, lipid hardening, to use cleaning fluid, repeatedly soften the failed sealing grease, and inject new grease replacement. In addition, sealing type and sealing material also affect the grease injection pressure. Different sealing forms have different grease injection pressure. Generally, the grease injection pressure of hard seal is higher than that of soft seal.