A starting point is the need to service some regulators. The ones shown are all Apeks regulators. (Actually there is also a domiflow oxygen valve on the right). These regulators are typical of diaphragm first stages. Other manufacturers will look very different but on the whole the principle of operation is the same and the servicing procedure is very similar.
Step 1 – Remove all the peripheral parts
By this I mean the contents gauge, inflation hoses and the second stages as well. Also remove the blanking plugs and any dust covers.
Note: that a numbered box is really useful to keep parts together and to identify the regulator if you are servicing more than one.
Step 2 – Remove dry seal and cylinder adapter
Use the special tool to lock the valve body. Once in place a large spanner can remove an A-clamp adapter or use an Allen key to remove the DIN adapters. The dry seal system can be removed using a pin spanner. This stage is not required with the non-sealed first stages.
Step 3 – Remove the IP adjuster
With the dry seal system removed the intermediate pressure adjuster can be removed with the spring below. Once this is done the top body part can be removed with a pin spanner. This reveals the diaphragm with its protective metal plate. This can be removed with the metal mushroom below.
Step 4 – Remove Valve seat
Now the turret can be removed with the valve seat assembly.
And that is it, the first stage disassembly is complete. Here is the exploded view: