DESCO CORPORATION
240 N. MILWAUKEE STREET
MILWAUKEE, WISCONSIN 53202
PHONE 414-272-2371
FAX 414-272-2373
www.divedesco.com
www.descocorp.com
DESCO Air Hat Air Train Installation Instructions
The DESCO Air Hat Air Train consists of the inside air elbow, copper tube, air control valve,
and air diffuser/muffler.
Installation:
Air Diffuser/muffler;
The Air Diffuser/muffler is loosely packed with Lambswool. It is pressed (using arbor press) or
screwed onto the outlet of the Air Control Valve with the holes faced 180 degrees away from the
valve stem.
Inside elbow;
Thread the inside elbow into the outside elbow 3-4 turns. It should screw in with little resistance.
Remove the inlet compression nut and ferrules in preparation for installing the copper tube.
Air Control Valve;
The cap, spacer, retaining nut, Brass washer, and two Lead washers are removed from the valve.
Place some tape on the valve stem to prevent the packing rings from falling off the stem.
Place one lead washer on the valve body and insert into the helmet snout. Place the second Lead
washer, Brass washer, and retaining nut on the valve. Leave the assembly loose for the next
assembly step.
Copper Tube;
To install the copper tube place the end with the longer straight length into the elbow, then line
the other end up with but outside of the valve inlet. Check the tube length. If it is too long
remove equal amounts from each end, and when the tube is the correct length deburr both ends.
The tube should have a small amount of end play when installed in the assembly before all is
secured.
Install the nuts, thin ferrules, then thick ferrules with the Stainless Steel ones to the valve, and the
brass ones to the elbow. The tapers on the ferrules should point to the tube ends.
Final Assembly;
Remove the copper tube and inside elbow. Using two part epoxy cement the inside elbow into
the helmet. The epoxy should be the 10 – 15 minute type to allow time for reassembly. Make
sure no epoxy covers the end of the valve or the opening in the helmet. A method of assuring
there is no epoxy blocking the opening is to blow compressed air into the double elbow from the
outside before the copper tube is reinstalled. Reinstall the copper tube and hand tighten all
joints. If the copper tube is in contact with the helmet shell place a piece of cardboard box under
the tube as a spacer. Allow the epoxy to completely set.
