Things to note when installing valve piping2020-03-05
What are the connection methods of valves and pipelines?2020-03-11
The manual valve, its handwheel or handle, is designed according to ordinary manpower, taking into account the strength of the sealing surface and the necessary closing force. Therefore, you cannot use a long lever or a long wrench to move. Some people are accustomed to using the wrench. Care should be taken not to apply excessive force or force, otherwise the sealing surface may be damaged, or the handwheel or handle may be broken. Open and close the valve, the force should be stable and not impact. Some parts of high-pressure valves that have been opened and closed due to shocks have considered such impact forces and ordinary valves cannot be equal. For the steam valve, before opening, it should be heated in advance and the condensed water should be eliminated. When opening, it should be slowed down as much as possible to avoid water hammer. When the valve is fully open, the handwheel should be turned upside down a little to tighten the threads tightly to avoid loose damage.
For bright-stem valves, remember the position of the stem when fully open and fully closed to avoid hitting the top dead center when fully open. And easy to check whether it is normal when fully closed. If the valve disc falls off, or if large debris is inserted between the valve core seals, the valve stem position will change when fully closed. For some media, after the valve is closed, it will cool down and cause the valve to shrink. The operator should close it again at an appropriate time so that there are no crevices on the sealing surface. . During operation, if it is found that the operation is too laborious, the cause should be analyzed. If the packing is too tight, it can be properly relaxed. If the valve stem is skewed, the personnel should be notified to repair it. Some valves, in the closed state, are subject to thermal expansion of the closing member, which makes it difficult to open; if it must be opened at this time, the valve cover can be loosened by half a turn to one turn to eliminate the valve stem stress, and then pull the handwheel.