Manual gear is the most widely used valve. Its hand wheel or handle is designed according to ordinary manpower. It considers the strength of the sealing surface and the necessary closing force. In this way, you cannot use a long rod or a long wrench to move. Some people are accustomed to using wrenches, so be careful not to use excessive force, otherwise it is easy to damage the sealing surface, or the wrenches may break wheels and handles.
When opening the valve, the force must be steady and not subject to impact. Some shock-activated high-pressure valve components have been considered, this kind of shock force cannot be withstood by ordinary valves. For the steam valve, before opening, it should be heated to remove the condensed water. When opening, it should be as slow as possible to avoid water hammer.
After the valve is fully opened, the handwheel should be turned upside down to tighten the threads to prevent the valve from loosening and damage. For rising stem valves, remember the position of the fully open and fully closed valve stems to avoid collisions between fully open and top dead center. And it is convenient to check whether the fully closed is normal. Assuming that the high-pressure solenoid valve falls off, or there is a large debris embedded between the valve core seal, the position of the valve stem will change when it is fully closed.
When the pipeline is first used, there are a lot of internal dirt. You can open the valve slightly, use the high-speed flow of the medium to flush it out, and then close it gently (do not close quickly, close it sharply to prevent residual impurities from getting stuck on the sealing surface) , This is repeated many times, the dirt can be returned to normal work after being washed away.
Frequently open the valve, the sealing surface may be stuck with dirt. When closing the valve, use the above-mentioned method to flush the dirt, and then formally shut it down. If the handwheel and handle are damaged or lost, they should be paired immediately and cannot be replaced with a movable wrench, so as not to damage the signal solenoid valve stem and make the four valve stems unable to open and close normally, causing production accidents.
Some media cool down after the valve is closed, which will cause the valve to shrink. The operator should close it again at an appropriate time so that the sealing surface does not leave any crevices. Otherwise, the medium will flow through the crevices at a high speed, which will easily erode the sealing components.
During the operation, if the operation is found to be too cumbersome, the reasons should be analyzed. The filling is too tight and can be properly loosened. If the valve stem is tilted, personnel should be notified for repair. In some valves, in the closed state, the closing part is heated and expanded, which makes it difficult to open; if you must open at this time, you can loosen the bonnet thread by half to one turn to eliminate the stress on the valve stem, and then use the plate to move the handwheel.