© ⅯⅯⅩⅢ Kirby Morgan Dive Systems, Inc. All rights reserved. Document # 130318002
21
Kirby Morgan
®
37SS
Chapter 2 - General Description
B
CAUTION
The fit of the Kirby Morgan helmets
is partially determined by the ad-
justment of the neck pad. If the neck
pad is not properly adjusted it may
be very uncomfortable on the diver’s
neck. Take the time to adjust the neck
pad properly and check the fit prior
to each dive to ensure the adjustment
has not changed.
2.8.5 Sealing Arrangement
The neck dam is available in several sizes and is
fabricated in a cone shape. The standard neck dam
on Kirby Morgan helmets is made of foam neoprene.
Optional latex neck dams are available.
The neck dam seals against the diver’s neck. The fit
of the neoprene neck dam may be made larger by
trimming. Only trim a maximum of ¼" at a time;
trimming too much will result in a loose fit.
B
WARNING
Pulling the neck dam over the diver’s
head can be difficult. Stretching (ex-
panding) the seal and placing it part
way over the head can help reduce
the force needed to install the seal.
Proper training is necessary to install
the neck seal over the diver’s head
and onto his neck. Although the possi-
bility is very remote, injury may result
if this procedure is not done properly.
If a diver does not know how to don
the neck dam, he must seek proper
instruction before proceeding.
NOTE: If you must trim the neck dam, be
careful not to trim off too much material. The
neck dam must fit snugly. While it may be a
slight bit uncomfortable out of the water, and
may feel snug, once in the water the neck
dam will loosen slightly due to compression
of the neoprene foam.
2.8.6 Reducing Carbon Dioxide
It is important to reduce the volume of air/gas space
that the diver is breathing through. Carbon dioxide
(
CO
2
) can build up if proper flushing does not occur.
A rubber oral nasal mask is located inside the helmet
to fit over the diver’s nose and mouth. The oral nasal
attaches to the regulator mount nut. This separates
the breathing gas flow from the larger gas space on
the interior of the helmet, and this in turn reduces
carbon dioxide buildup.
B
WARNING
Always be sure the oral nasal valve
is properly mounted in the oral nasal
mask. If the valve is mounted improp-
erly or is absent this can lead to a
higher CO
2
level inside the helmet. A
higher CO
2
level can cause dizziness,
nausea, headaches, shortness of
breath, or blackout.
2.8.7 Communications
In Kirby Morgan helmets, both earphones and micro-
phone are wired in parallel to the communications
module. This module allows for rapid replacement of
the entire communications system. The module can
be equipped with either a waterproof connector, or
binding posts for bare wire connection.
Kirby Morgan uses only high quality speakers and
microphones in its communication system, to help
ensure the clearest possible communications.
2.8.8 Equalizing the Middle Ear
A nose block device allows the diver to block his
nose to provide an overpressure in his middle ear for
equalization. The blocking pad on the inside of the
oral nasal mask is attached to a shaft which passes
through a packing gland to the outside of the helmet.
A knob attached to the end of the shaft can be pushed
in to slide the pad under the diver’s nose.
Nose Block Device
Nose Block
Knob
Oral Nasal Mask
Port Retainer
O-ring
O-ring
O-ring
Packing Nut
When not needed, the knob is pulled out so the pad
does not rub under the diver’s nose. The pad may also
be turned upside down (to provide more clearance
under the diver’s nose) by rotating the shaft.
