Valve maintenance methods

refer to: http://bbs.hcbbs.com/thread-41289-1-1.html Additional explanation: The general maintenance sequence of valve maintenance is relatively fixed. 1. Loosen the connections of all accessories on the valve body, and loosen the valve body bolts on both sides (haha, I think this is nonsense). 2. Disengage the diaphragm head and valve body, loosen the pre-tightening first if there is pre-tightening. 3. Check the diaphragm head and do an air tightness test. If there is air leakage, check the diaphragm, push rod, and O-ring. 4. Open the valve cover and check the valve internal parts: whether the valve core and valve seat are washed away or strained, and whether there are scars on the sealing surface. The treatment method is generally grinding and auto-fitting. If there are scratches, first grind out the valve seat and match the auto-fitting valve core (if the problem is not serious). Note After assembly, the valve core still needs to be ground with the valve seat. Use red red powder to confirm whether the sealing surface is in contact. The common problems of the valve stem are strain and bending, or detachment and disconnection from the valve core. These problems are easy to deal with. If there is erosion in the valve body, the treatment method is generally surfacing and auto assembly. Finally, assemble the valve body and do a pressure leakage test, refer to the current * * Or the leakage standard of the industry. (Note that valves with special requirements, such as oil-free valves, must use carbon tetrachloride to clean the inside, use nitrogen to do a pressure leakage test, and wrap the valve flange). 5. Connect the diaphragm head and valve body (pay attention to pre-tightening), reset on line, connect the accessories, monotonous, and joint debugging.

What you can do is to replace the gasket of the large cover and the packing of the valve seal. If there is a problem with the sealing surface of the valve body, you will have to contact the manufacturer or scrap it.