Valves are not only widely used in various industries, but also the use of different environments, and some valves in harsh working environments are prone to problems. Because valves are important equipment, especially for some large valves, once a problem needs to be repaired or replaced, it is quite troublesome. So do a good job of daily maintenance and maintenance is particularly important. Let's take a look at some knowledge about valve maintenance.

First, valve storage and daily inspection

1, the valve should be stored in a dry and ventilated room, and both ends of the channel should be blocked.

2, long-term storage valve should be regularly checked, remove dirt, and apply anti-rust oil on the processing surface.

3, after installation, should be regularly inspected, the main inspection items: (1) sealing surface wear. (2) The trapezoidal thread wear of the valve stem and valve stem nut. (3) Whether the packing is outdated and ineffective, if there is damage, it should be replaced in time. (4) After the valve repair and assembly, the sealing performance test should be carried out.

The professional maintenance work of the valve before and after the welding operation plays a vital role in the production and operation of the valve. Correct and orderly and effective maintenance will protect the valve, make the valve function normally and extend the service life of the valve.

Valve maintenance work seems simple, in fact, it is not. There are often overlooked aspects of work:

First, when the valve grease is injected, the problem of the amount of grease is often ignored. After oil injection, the operator chooses the valve and grease injection connection mode, and carries out grease injection operation. There are two situations: on the one hand, the amount of fat injection is small, and the sealing surface is accelerated by the lack of lubricant. On the other hand, excessive fat injection causes waste. 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 category, and then the appropriate amount of grease can be injected reasonably.

Second, the valve grease, often ignore the pressure problem. During the operation of grease injection, the pressure of grease injection changes regularly with peaks and valleys. If the pressure is too low, the seal leakage or failure pressure is too high, the grease injection port is blocked, the grease in the seal is hardened, or the sealing ring is locked with the valve ball or valve plate. Usually when the grease injection pressure is too low, the injected grease flows into the bottom of the valve chamber, which generally occurs in small gate valves. The grease injection pressure is too high, on the one hand, check the grease injection nozzle, if the fat hole is blocked, replace it; On the other hand is the hardening of grease, to use a cleaning solution, repeatedly soften the failed sealing grease, and inject new grease replacement. In addition, the sealing model and sealing material, also affect the injection pressure, different sealing forms have different injection pressure, in general, the hard seal injection pressure is higher than the soft seal.

Do the above work, I believe that it is very helpful to extend the service life of the valve, and can also reduce a lot of unnecessary trouble.