Step 1 – Remove the handle
This is done with a special flat bladed tool that straddles the centre thread. This one is in fact made from a flat bit. This is done so that it can be attached to an impact driver, as they can become difficult to remove after a couple of years use. The nut once removed allows the spring, then the handle and finally the nylon washer to be removed.
Step 2 – Remove the screw mechanism
Next the screw mechanism is removed. This is done by unscrewing the nut at the end of the valve. Once removed the spindle should be removed from the cylinder valve. There is a nylon washer on the shaft and o’ring seals at either end of the body.
Step 3 – Valve Seat
The final step is to remove the valve seat itself. There are various types. Some are all nylon whilst others like the one pictured are brass with a nylon face. This one has a slot in the back that the blade on the spindle fits into. Others are the reverse with the spindle having a saddle that fits over a flat on the back of the seat. All are basically the same.
Step 4 – Remove the cylinder valve
Lastly a tool is inserted into the valve and very delicately loosened with the aid of a large hammer. A-Clamp valves have an adapter that fits over the body to allow the DIN tool to be used. Spanners are not recommended as they will damage the chrome and brass of the valve.
These parts are then put to one side, cleaned and serviced with new O’rings. Information on cleaning can be found here which details cleaning of a regulator first stage