The reasons why valves can't be tightly closed
If a sanitary valve can’t be tightly closed, we should first find out what the problem is, then solve the problem according to the corresponding methods. General reasons why a valve can’t be tightly closed include the following:
(1) there are impurities stuck in the sealing surface, debris deposited in the bottom of the valve or rested between the valve flap and the valve seat.
(2) thread of the valve stem rusted, the valve cannot rotate.
(3) the sealing surface of the valve is damaged, resulting in media leakage.
(4) the valve stem and valve flap are not properly connected, so that the valve flap and valve seat cannot be tightly connected.
Measures to deal with the problem that valves can’t be tightly closed:
1. there are impurities stuck in the sealing surface
Valves sometimes can’t be tightly closed, that may be because there are impurities stuck in the sealing surface. In this case, one should not use forced closure. The valve should be opened slightly wider, and then be close. Try this again and again, usually the problem can be fixed. Otherwise one should check the valve and ensure the medium is clean.
2. thread of the valve stem rusted
For valves that are normally open, in the event of accidental closing, since the stem threads are already rusted, it can’t be tightly closed as well. In this case, you can repeatedly switch open and closed the valve several times while knocking the bottom of the valve with a hammer, which can shut close the valve without the need to grind the valve.
3. the sealing surface of the valve is damaged
When the valves still can’t be tightly closed after several tries, then the sealing surface is already damaged and needs to be repaired; or corrosion, scratches by the particles in the medium damage the sealing surface, which also needs repair.
4. the valve stem and valve flap are not properly connected
Regularly lubricate the valve stem and valve stem nut to ensure the flexibility of the valve switch.