Daily valve maintenance
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(3) Whether the packing is outdated and invalid, if damaged, it should be replaced in time.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 SINGLE UNION BALL VALVE X9201-T GREY is overhauled and assembled, the sealing performance test should be carried out.
Maintenance work during valve grease injection
The maintenance work of the valve before welding and after it is put into production plays a vital role in 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 calculation for different valve sealing capacities 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 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 hard seal grease injection pressure should be the best soft seal.
3. When injecting grease into the valve, pay attention to the problem that the valve is in the switch position. The ball valve is generally in the open position during maintenance, and in special cases, it is selected to be closed for maintenance. Other valves can not be regarded as open position. The gate valve must be closed during maintenance to ensure that the grease fills the sealing groove along the sealing ring. If it is opened, the sealing grease will fall directly into the flow channel or valve cavity, causing waste.
Fourth, when the valve is greased, the effect of grease injection is often ignored. During the grease injection operation, the pressure, grease injection volume, and switch position are all normal. However, in order to ensure the grease injection effect of the valve, it is sometimes necessary to open or close the valve, check the lubrication effect, and confirm that the surface of the valve ball or gate plate is evenly lubricated.
5. When injecting grease, pay attention to the problem of valve body drainage and wire plugging pressure relief. After the valve pressing test, the gas and water in the valve cavity of the sealing cavity will be boosted due to the increase of the ambient temperature. When the grease is injected, it is necessary to discharge the sewage and release the pressure, so as to facilitate the smooth progress of the grease injection. The air and moisture in the sealed cavity are fully replaced after grease injection. The valve cavity pressure is released in time, which also ensures the safety of the valve. After the grease injection, be sure to tighten the drain and pressure relief plugs to prevent accidents.
6. When injecting grease, pay attention to the problem of uniform grease. During normal grease injection, the grease discharge hole closest to the grease injection port will discharge grease first, then to the low point, and finally to the high point, and the grease will be discharged one by one. If it does not follow the rules or there is no fat, it proves that there is a blockage, and it should be cleaned in time.
7. When injecting grease, also observe that the valve diameter is flush with the sealing ring seat. For example, for a ball valve, if there is interference in the opening position, adjust the opening position limiter inward to confirm that the diameter is straight and then lock. Adjusting the limit should not only pursue the opening or closing position, but consider the whole. If the opening position is flush and the closing position is not in place, the valve will not close tightly. In the same way, if the adjustment of the closed position is in place, the corresponding adjustment of the open position should also be considered. Make sure the valve has a right angle of travel.
8. After grease injection, be sure to seal the grease injection port. To avoid the entry of impurities, or the oxidation of lipids at the grease injection port, the cover should be coated with anti-rust grease to avoid rusting. for the next operation.
9. When injecting grease, consideration should also be given to the specific treatment of specific problems in the sequential transportation of oil products in the future. Given the different qualities of diesel and gasoline, the scour and disintegration ability of gasoline should be considered. In the future valve operation, when encountering gasoline section operations, the grease should be replenished in time to prevent the occurrence of wear.
10. When injecting grease, do not ignore the grease injection at the valve stem. There are sliding bushings or packings on the valve shaft, which also needs to be kept lubricated to reduce the frictional resistance during operation. If lubrication cannot be ensured, the torque will increase the wear parts during electric operation, and the switch will be laborious during manual operation.
11. Some ball valves are marked with arrows. If there is no English FIOW handwriting, it is the direction of action of the sealing seat, not as a reference for the flow direction of the medium, and the direction of the valve self-leakage is opposite. Typically, double seated ball valves have bidirectional flow.
12. When maintaining the valve, also pay attention to the problem of water inflow in the electric head and its transmission mechanism. Especially the rain that seeps in during the rainy season. One is to rust the transmission mechanism or the transmission sleeve, and the other is to freeze in winter. When the electric valve is operated, the torque is too large, and the damage to the transmission parts will make the motor no-load or the maximum torque protection trip, and the electric operation cannot be realized. The transmission parts are damaged, and manual operation cannot be carried out. After the high torque protection action, manual operation is also unable to switch, such as forced operation, it will damage the internal alloy parts.
In summary, valve maintenance is really treated with a scientific attitude, so that the valve maintenance work can achieve its due effect and application purpose.
Post time: Jan-26-2022