Desco 61000, Manual

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Disassembly and Reassembly:
The Air Hat can be completely disassembled using a screwdriver and wrench. The headpiece assembly is held
in the Air Hat by a single #10-32 hex nut in the center of the top band. To remove the headpiece assembly
unscrew the hex nut as pull the headpiece assembly out by the side opposite the air control valve. Backing out
or removing the communications binding posts will ease removal.
To replace the headpiece assembly insert the side at the air control valve first making sure it is clear of the
copper tube. Rock the assembly in till the top band is over the retaining stud, then check the assembly is aligned
left and right by gauging the distance between the snout/shell seam and the front end of the side pads. Replace
and tighten the hex nut.
To remove the copper air distribution tube, first loosen the air control valve-retaining nut so that the valve will
rotate freely. Secondly, completely unscrew the compression nuts at both ends of the copper tube and rotate the
valve body counter clockwise until the tube drops free. If the tube is undamaged it can be reused. If replacement
is necessary the compression ferrules will also have to be replaced. A set of stainless steel ferrules are used on
the valve end, and a set of brass ferrules on the elbow end. The small ferrule goes on first, then the larger one
with the tapers on both pointing towards the end of the tube.
WARNING: Teflon tape should never be used on any part of the Air Hat. The possibility exists for pieces
of Teflon tape to enter the air delivery system and cause a blockage.
Removal and installation of the other components of the Air Hat are obvious from inspection and require no
special instructions.
To Adjust Headpiece Insert for Head Size:
Size adjustments to the headpiece assembly are made with the assembly removed from the Air Hat. Loosen the
two brass screws on the upper edge of the back plate at the rear of the assembly. The proper fit is achieved by
changing the circumference of the headpiece assembly, by sliding the back band in or out. The headpiece
should fit snugly on the diver’s head, as the liner will compress somewhat under pressure. When the correct fit
is achieved tighten the two screws and reinstall in the Air Hat.
To Replace Foam Neoprene Pads on Headband Assembly:
All new Air Hats use an improved Headpiece Assembly utilizing Polypropylene band, which are impervious to
corrosion, unlike the brass bands of earlier Air Hats. The side pads are attached to the side band with pressure
sensitive tape making replacement simpler. The top pad is held in place by the top band passing through a slot
in the top. To change the pads remove the liner from the Air Hat. It is held in by a # 10 – 32 hex nut in the
center of the top pad. Peel off the old side pad and discard. Unbolt one side of the top band and slide off the old
top pad. Slide the new top pad into place and rebolt the top band. Clean any oil, grease, dirt, or old adhesive
from the area where the new side pads will go. You can use Denatured Alcohol or Lacquer Thinner to clean the
area. Make sure all the solvents are completely gone before using the Air Hat again. Peel the paper backing
from the new side pad and press firmly into place. As you reinstall the liner into the Air Hat make sure the top
pad is centered on the retaining stud hole in the top band. Watch the side pads as you install the liner so they do
not roll as you press the liner into place. Check the liner to make sure it is centered in the Air Hat and replace
and tighten the hex nut.
How to Choose the Proper Size of Neck Dam:
Neck Dams are available in sizes 12 through 15. The appropriate size is approximately two sizes smaller than
the diver’s regular collar size. Thus, a diver who wears a size 16 collar should use a size 14 Neck Dam. Custom
sized Neck Dams are available upon request.
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