Reasons and treatment methods for valve not being closed tightly

In the process of using the valve, some disturbing problems often occur, such as the valve is not closed tightly or tightly. What should we do?
Generally, if the valve is not tightly closed, first check whether the valve is closed in place. If there is still leakage that cannot be sealed after it is closed in place, then check the sealing surface. If the sealing pair of some valves is removable, then take it out for grinding and retest. Of course, if it is still not tightly closed, then return to the factory for maintenance or replacement of the valve, In order to avoid problems such as affecting the normal use of the valve and occurrence of working condition accidents.
If the valve is not closed tightly, first find out where the problem is, and then solve it according to corresponding methods. There are several reasons why the valve can not be closed tightly:
(1) There are impurities stuck on the sealing surface, which are deposited at the bottom of the valve or between the valve disc and valve seat;
(2) The valve stem thread is rusty and the valve cannot rotate;
(3) The sealing surface of the valve is damaged, resulting in medium leakage;
(4) The connection between valve rod and valve disc is not good, so that the valve disc and valve seat cannot be in close contact with each other.
Treatment method for valve not closed tightly:
1、 The valve sealing surface is blocked by impurities
Sometimes the valve is suddenly not closed tightly. It may be that there are impurities stuck between the sealing surfaces of the valve. At this time, force should not be used to close the valve. Open the valve slightly, and then try to close it again and again. Generally, it can be eliminated. Otherwise, check should be carried out to keep the quality of the medium clean.
2、 Rust on valve rod thread
For the valve that is normally in the open state, when it is accidentally closed, the valve rod thread has rusted, and it will not be closed tightly. In this case, you can repeatedly open and close the valve several times, and knock the bottom of the valve body with a small hammer at the same time, that is, you can close the valve tightly without grinding and repairing the valve.
3、 The sealing surface of the valve is damaged
If the switch cannot be closed tightly after many attempts, the sealing surface has been damaged and should be reported for repair; Or if the sealing surface is damaged by corrosion or particle scratch in the medium, it should also be reported for repair.
4、 Poor connection between valve rod and valve disc
Add lubricating oil to the valve rod and valve rod nut frequently to ensure the flexible opening and closing of the valve. There should be a formal maintenance plan.