In general, if it is not tightly closed, first check whether the valve has been closed in place. If the leak cannot be sealed after it has been closed in place, then check the sealing surface. For some valves, the sealing pair is detachable, so take it out for grinding and test again. If it is still not strictly closed, it must be returned to the factory for repair or replacement of the valve, so as not to affect the normal use of the valve and the occurrence of working conditions and other problems.
If the valve is not tightly closed, you should first find out where the problem is, and then solve it according to the corresponding method.
The reasons for the valve not being tightly closed are generally as follows:
(1) There are impurities stuck on the sealing surface, and debris is deposited at the bottom of the valve or cushioned between the valve disc and the valve seat;
(2) The valve stem thread is rusted, and the valve cannot rotate;
(3) The sealing surface of the valve is damaged, causing the medium to leak;
(4) The valve stem and the valve disc are not well connected, so that the valve disc and the valve seat cannot be in close contact with each other.
The valve is not closed tightly
I. Impurities jam the valve sealing surface
The valve sometimes suddenly closes improperly. It may be due to impurities stuck between the sealing surfaces of the valve. At this time, the valve should not be forced to close. Open the valve slightly larger, and then try to close it. Repeatedly try to eliminate it. Check again. The quality of the media should also be kept clean.
Two, valve stem thread is rusted
For a valve that is normally open, when it is closed accidentally, the valve may not close tightly because the thread of the valve stem is rusted. In this case, you can repeatedly open and close the valve several times, and at the same time hit the bottom of the valve body with a small hammer, you can close the valve tightly, without grinding and repairing the valve.
Third, the valve sealing surface is damaged
For the case where the switch is still not tightly closed after multiple attempts, that is, the sealing surface is damaged, or the sealing surface is damaged due to corrosion, particle scratches in the medium, etc., this situation should be reported for repair.
Fourth, the valve stem and valve disc connection is not good
In this case, you need to lubricate the stem and stem nut to ensure that the valve can be opened and closed flexibly. There must be a formal maintenance program to strengthen the maintenance of the valve.