Now that all the parts are cleaned we can start the process of assembly. First we get all the parts and tools together.

Step 1 – Diaphragm End

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Take the main body and drop the mushroom into the body. The diaphragm can then be pushed into place and the metal disk that the spring sits on goes next. The top part of the body can now be fixed ensuring that the body does not clamp onto the disk. Set the body upright and make sure it is free to move in its housing. Then tighten down with the pin spanner.

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The main spring goes in next and must sit on the metal disk centrally. Then screw down the adjuster so that it is almost flush with the body. This pushes the spring and so the mushroom down

Step 2 – Valve Seat Assembly


This is the only tricky bit. Grease and press the small O’ring into the top of the body. Also fit the medium sized O’ring around the middle.  The spring goes on and then push the valve seat into the centre of the small O’ring. That’s it. The larger O’ring and bearing washer is in fact easier to fit at the next step.

Step 3 – Turret Assembly


Grease the large turret washer and fit to the body. Place the turret on top. Then fit in the blue bearing washer and larger Valve O’ring into the top. With the valve upright the valve assembly can be dropped down into the body so that the hole in the seat itself sits on the mushroom from the other side. A small amount of pressure is needed to push down to be able to tighten everything up.

The turret O’rings are the main moving parts and may need a bit more grease. All other O’rings should have just sufficient for assembly.

It is very important to assemble the diaphragm end before the turret as the spring keeps the seat of the knife edge in the body. If that is damaged it is likely to be the end of the valve.

Step 4 – A-Clamp or DIN fitting

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There is a slight difference between the two systems. For the A clamp the white filter is pressed into the shaft from the “cylinder” end. The DIN fitting has a cone shaped filter inserted from the “valve” end.  With the filter in place the shaft goes through the A-clamp or DIN fitting through the plastic spacer and screwsinto the main body with the O’ring in to seal. It is best to put it all together and hold everything upright to screw into the body as the O’ring can easily pop out and be damaged when tightened.

Step 5 – Attach the peripheral parts.

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Step 5 – Testing

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With everything back together the valve is connected to an air supply. This should be around 70 Bar and not a full cylinder.  For the first time at least it is a good idea to press the purge on the second stage when applying the pressure to bring the pressure up slowly. Purge the valve several times to allow for a bit of settling.

Attach a pressure gauge to one of the intermediate ports. Adjust the pressure using the allen key to the required pressure. This is typically between 9 and 10 Bar, but may vary due to the application. It is better to purge the air first before each adjustment.

Step 5 – Refit dry seal


Lastly the dry seal system can be attached with the new service date sticker fitted to below the clear plastic membrane.

The second stages may also need adjustment to match the new interstage pressure.