During the use of high vacuum stainless steel diaphragm valves, some troublesome problems often occur, such as the valve not closing tightly. What should we do?
In general, if the valve is not tightly closed, first check whether the valve is closed in place. If the seal is in place, there will still be leaks that cannot be sealed. Then check the condition of the sealing surface. Some valve seals are detachable, take them out and grind them before conducting experiments. Of course, if the valve is still not tightly closed, it needs to be returned to the factory for repair or replaced to avoid affecting the normal use of the valve and causing work accidents and other problems.
If the valve is in a relaxed state, first identify where the problem lies, and then take corresponding measures to deal with it. Usually, valves do not close correctly due to the following reasons:
1. Impurities are stuck on the sealing surface, deposited at the bottom of the valve or placed between the valve disc and seat;
2. Rust on the valve stem thread prevents the valve from rotating;
3. The sealing surface of the valve is damaged, resulting in leakage of the medium;
4. The connection between the valve stem and the valve disc is not good, causing the valve disc to deviate and not be in close contact with the valve seat.
Handling methods for valves that are not tightly closed:
1. Impurities are stuck on the sealing surface of the valve
Sometimes the valve may not be tightly closed, which may be due to impurities stuck between the sealing surfaces of the valve. At this time, force should not be used to forcibly close the valve. The valve should be slightly opened larger and then attempted to close again. Repeat the test to eliminate the problem. Otherwise, it should be checked and the quality of the medium should be kept clean.
2. Rust on valve stem threads
Regarding valves that are usually in an open state, occasionally when closed, they may not close tightly due to rust on the valve stem threads. Regarding this situation, the valve can be repeatedly opened and closed several times, while tapping the bottom of the valve body with a small hammer to tightly close the valve without the need for grinding or repairing the valve.
3. The sealing surface of the valve is damaged
If the switch still cannot be tightly closed after multiple attempts, it indicates that the sealing surface is damaged and should be reported for repair; Or if the sealing surface is damaged by corrosion, scratches from particles in the medium, etc., it should also be reported for repair.
4. Poor connection between valve stem and valve disc
Regularly lubricate the valve stem and stem nut to ensure flexible opening and closing of the valve. There must be a formal maintenance plan.
