First, when the valve is greased, the problem of grease injection is often ignored. After the grease injection gun is refueled, the operator selects the valve and the grease injection connection method, and then performs the grease injection operation. There are two situations: on the one hand, the amount of grease injection is small and the grease injection is insufficient, and the sealing surface wears quickly due to the lack of lubricant. On the other hand, excessive grease injection results in waste. The reason is that there is no precise calculation of the sealing capacity of different valves according to the valve type category. The sealing capacity can be calculated according to the valve size and type, and then a reasonable amount of grease can be injected.

Second, when the valve is greased, the pressure problem is often ignored. During the grease injection operation, the grease injection pressure changes regularly with peaks and valleys. The pressure is too low, the seal leaks or fails, the pressure is too high, the grease injection port is blocked, the sealing inner grease is hardened, or the sealing ring is locked with the valve ball and valve plate. Usually, when the grease injection pressure is too low, the injected grease mostly flows into the bottom of the valve cavity, which usually occurs in small gate valves. If the grease injection pressure is too high, on the one hand, check the grease injection nozzle, and replace it if the grease hole is blocked. . In addition, the sealing type and sealing material also affect the grease injection pressure. Different sealing forms have different grease injection pressures. Generally, the grease injection pressure of hard seals is higher than that of soft seals.