Without any additional oil lubrication, hydraulic control valve
can use water to do the lubrication itself. If there is something wrong with the components of the main valve, please follow these instructions to do the disassembly.
(Note: The diaphragm and O ring are usually damaged a lot and other internal parts are rarely damaged)
1. Firstly, close the gate valves which are on the front and rear ends of the main valve.
2. Then, loosen the screws of the pipe connectors so as to release the pressure.
3. Remove all the metal screws, including the nuts of the necessary copper pipes in the control pipeline.
4. Take the bonnet and spring down.
5. Then, take the shaft, diaphragm, and piston down, too. Remember not to damage the diaphragm.
6. After removing all the things above, you need to check weather the diaphragm and O ring are damaged or not.
7. If there is something wrong with the diaphragm or O ring, please loosen the nuts on the spool core, take the diaphragm or O ring out carefully, and then change a new one instead.
8. Detailed inspection for the seat, shaft and other parts of the main valve
should be carried out. And if there is any debris inside the main valve, timely cleanup is necessary.