The reason and treatment of valve not closed tightly

In the process of using the valve, there are often some troubling problems, such as the valve is not closed tightly, how to do?

In general, if it is not closed tightly, first confirm whether the valve is closed in place. If there is leakage after it is closed in place, then check the sealing surface. If the sealing pair of some valves is detachable, then take it out for grinding and test again. Of course, if it is not closed tightly, It must be returned to the factory to repair or replace the valve, so as not to affect the normal use of the valve and the occurrence of accidents and other problems.

If the valve is not closed tightly, we should first find out where the problem is, and then solve it according to the corresponding methods. Generally, the valve is not closed tightly due to the following reasons:

(1) There are impurities stuck on the sealing surface and deposited at the bottom of the valve or between the valve disc and the valve seat;

(2) The stem thread is rusty and the valve can't rotate;

(3) The sealing surface of the valve was damaged, resulting in the leakage of the medium;

(4) The connection between the valve stem and the valve disc is not good, so that the valve disc and the valve seat can not be in close contact.

Treatment method for valve not closed tightly:

1、 Impurities stuck on valve sealing surface

Sometimes the valve is suddenly not closed tightly, which may be due to impurities stuck between the sealing surfaces of the valve. At this time, the valve should not be forced to close by force. The valve should be opened a little larger, and then try to close it again and again. Generally, it can be eliminated, otherwise, it should be checked, and the quality of the medium should be kept clean.

2、 Stem thread rusty

For the valve which is usually in the open state, when it is closed accidentally, because the stem thread has been rusted, it will not be closed tightly. In this case, the valve can be opened and closed several times, and the bottom of the valve body can be knocked with a small hammer, that is, the valve can be closed tightly without grinding and repair.

3、 The sealing surface of the valve is damaged

If the switch fails to be closed after several 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 stem and disc

Often add lubricating oil to the valve stem and stem nut to ensure the valve opening and closing flexibility. There should be a formal maintenance program.