Valves are not only widely used in various industries, but also used in different environments. Some valves in harsh working environments are prone to problems. Since the valve is an important equipment, especially for some large valves, it is quite troublesome to repair or replace once a problem occurs. Therefore, it is very important to do daily maintenance and maintenance. Let’s take a look at some little knowledge about valve maintenance.
A. Storage and daily inspection of valves
1. The valve should be stored in a dry and ventilated room, and both ends of the passage must be blocked.
2. Valves that have been stored for a long time should be checked regularly, the dirt should be removed, and anti-rust oil should be applied to the processing surface.
3. After installation, regular inspections should be carried out. The main inspection items:
(1) The wear of the sealing surface.
(2) The wear of the trapezoidal thread of the stem and stem nut.
(3) Whether the packing is outdated and invalid, if damaged, it should be replaced in time.
(4) After the valve is repaired and assembled, the sealing performance test should be carried out.
B. Maintenance work during valve grease injection
The professional maintenance of the valve before and after the welding plays a vital role in serving the production and operation of the valve. Correct, orderly and effective maintenance will protect the valve, make the valve function normally and prolong the service life of the valve. life. Valve maintenance work may seem simple, but it is not. There are often overlooked aspects of work.
1. When injecting grease into the valve, the amount 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 different valve sealing capacity 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.
2. 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 the failure 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.
Doing the above work is believed to be very helpful to prolong the service life of the valve, and at the same time, it can also reduce a lot of unnecessary troubles.
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Post time: Jul-20-2022