1. The pump valve castings shall be stored in a dry and ventilated room, and both ends of the passage shall be blocked.
2. The pump valve castings stored for a long time should be inspected regularly, the dirt should be removed, and the processing surface should be coated with antirust oil.
3. After installation, regular inspection shall be carried out. Main inspection items are as follows:
(1) Wear condition of sealing surface.
(2) Trapezoidal thread wear of stem and stem nut.
(3) Whether the packing is out of date and invalid, and if it is damaged, it should be replaced in time.
(4) After maintenance and assembly of pump valve castings, sealing performance test should be carried out.
Maintenance of pump valve castings during grease injection
The professional maintenance of pump valve castings before and after welding plays an important role in serving the production and operation of pump valve castings. Correct, orderly and effective maintenance will protect the pump valve castings, make the pump valve castings function normally and prolong the service life of pump valve castings. The maintenance of pump valve casting seems simple, but it is not. There are often neglected aspects in work.
First, when the pump valve casting is greased, the problem of the amount of grease is often ignored. After the grease gun is filled with oil, the operator selects the pump valve casting and the grease connection mode to carry out the grease injection operation. There are two situations: on the one hand, the amount of grease injection is less, and the sealing surface is worn faster due to the lack of lubricant. On the other hand, excessive fat injection causes waste. The reason is that the sealing capacity of different pump valve castings is not accurately calculated according to the type and category of pump valve castings. The sealing capacity can be calculated according to the size and type of pump valve casting, and then a reasonable amount of grease can be injected.
Second, the pressure problem is often ignored when the pump valve casting is greased. During the operation of fat injection, the pressure of fat injection changed regularly from peak to valley. If the pressure is too low, the seal leaks or fails, the pressure is too high, the grease injection port is blocked, the grease in the seal is hardened, or the seal ring is locked with the valve ball and valve plate. Usually, when the grease injection pressure is too low, the injected grease flows into the bottom of the valve chamber, which usually occurs in small gate valves. On the one hand, check the grease nozzle, if the grease hole is blocked, judge the situation and replace it; On the other hand, it is the hardening of grease. It is necessary to use cleaning fluid to soften the failed sealing grease repeatedly and inject new grease for replacement. In addition, seal type 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.