When valve is greased, pressure shall also be considered. During the grease injection operation, the grease injection pressure regularly changes from peak to valley. The pressure is too low, the seal leakage or failure pressure is too high, the grease injection port is blocked, the grease inside the seal is hardened, or the seal ring is locked with the valve ball and valve plate. Generally, when the grease injection pressure is too low, the injected grease mostly flows into the bottom of the valve chamber. Although this is most likely to happen to small gate valves, full welding is also possible. If the grease injection pressure is too high, on the one hand, check the grease injection nozzle, and if the grease hole is blocked, judge the situation and replace it; On the other hand, it is necessary to use cleaning fluid to harden the failed sealing grease repeatedly and inject new lubricating grease for replacement. In addition, the seal model and seal material also affect the grease injection pressure. Different seal forms have different grease injection pressure. Generally, the grease injection pressure of hard seal is higher than that of soft seal.

(5) Check the condition of parts again;