The reason and treatment of the pneumatic control valve is not tight

The reason and treatment of the pneumatic control valve is not tight

April 22, 2019

Pneumatic control valves often present some troublesome problems during use. For example, if the pneumatic control valve is not tight and the door is not tight, what should I do?

Under normal circumstances, if it is not critical, first check to see if the valve is closed. If it is closed, it is still leaky and can not be sealed. Then look at the sealing surface condition, some valve sealing pair It is detachable, so take it out for grinding and experiment again. Of course, if it is still not tight, then it is necessary to return to the factory for repair or replace 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 tight, you should first find out where the problem is, and then deal with it according to the corresponding method. There are several reasons why the general valve is not tight:

  1. Impurities are stuck on the sealing surface, and debris is deposited at the bottom of the valve or between the valve disc and the valve seat;
  2. The 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 are not in close contact with each other.

The valve is not tightly handled:

  • There are impurities stuck in the valve sealing surface
    Sometimes the valve is not tightly closed. It may be that there is impurity jam between the sealing surfaces of the valve. At this time, the force is forcibly closed. The valve should be slightly opened, and then try to close it. Repeat the test. Generally, it can be eliminated. Otherwise, it should be For inspection, the quality of the media should be kept clean.
  • Stem thread rust
    With regard to valves that are normally open, occasionally closed, the valve stem threads are now rusted and can be severely closed. In this case, the valve can be repeatedly switched and closed, and the bottom of the valve body can be struck with a small hammer, so that the valve can be closed and the valve can be repaired without grinding.
  • Valve sealing surface is damaged
    Regarding the situation in which the switch is still closed, the sealing surface is damaged and should be repaired; or the corrosion, the grain in the medium, etc., may damage the sealing surface and should be repaired.
  • The valve stem is not well connected to the valve disc
    The stem and stem nut are often lubricated to ensure flexible valve switching. Have a formal maintenance plan.