Auxiliary Gas Supply System - Kirby Morgan KMB-18 A/B Operation And Maintenance Manual

All Kirby Morgan Helmets and Bandmasks are
equipped with a multi turn demand regulator
adjustment knob. The purpose of this adjustment
knob is to allow the diver the ability to compen-
sate for variations in umbilical supply pressure.
This adjustment device operates by simply in-
creasing or decreasing the amount of spring bias
tension on the demand regulator inlet valve. The
adjustment knob has a range of approximately 13
turns from full in to full out. The intent of this bias
adjustment device is strictly to allow the diver to
make adjustments for variations in umbilical sup-
ply pressure. This adjustment device is not in-
tended as a minimum-maximum device. Mini-
mum and maximum applies to supply pressure
only. The adjustment knob should be adjusted by
the diver to be at the easiest breathing setting at all
times. The exact number of turns required is
dependent on the supply pressure. Diving a
KMDSI helmet or bandmask with a bias setting
greater than that just necessary to keep the de-
mand valve from free flowing increases the work
of breathing and reduces the diver's ability to
perform heavy work.
The adjustment knob (47) allows the diver to
control the regulator for a wide range of incoming
gas pressures. Normally, this would be from 115
P.S.I. to 225 P.S.I. over ambient (diver) pressure.
It is important to have this control at the diver for
the least breathing resistance.
The Kirby Morgan Band Mask 18B and KMB 28
side block is drilled and tapped to accept low
pressure inflator hoses. This allows the diver the
capability to inflate variable volume dry suits or
buoyancy compensators. It is tapped with a 3/8"-
24 thread orifice, standard for American first
stage scuba regulator low pressure auxiliary fit-
tings. The port is shipped plugged at delivery.
Document # 010518001 © Copyright 1970-2003 Kirby Morgan Dive Systems, Inc. All rights reserved.
KMB 18 & 28 MANUAL
WARNING: When using the side
block low pressure inflator port. The Op-
erator should only use high quality hoses
with an integrated flow restrictor or a
KMDSI flow restrictor PN# 555-720. All
hoses must have an in-line restrictor to
reduce the gas flow in the event of hose
failure. Do not use fitting adapters, stan-
dard adapters do not provide an adequate
flow restriction. The use of many off the
shelf adapters on the side block assem-
bly could expose the low pressure hose
fittings to excessive stress. Any failure of
an inflation hose will subject the diver to
a decreased supply pressure.

1.5.2 Auxiliary Gas Supply System

All divers using Kirby Morgan surface supplied
helmets and masks must always have a diver
worn auxiliary gas cylinder fitted with a first stage
regulator and hose that is connected to the inlet
of the auxiliary supply valve (103). The size of
the cylinder should be such that will allow the
diver to safely ascend to the surface or to a point
where the normal gas supply can be restored. The
first stage regulator should always be fitted with
the KMDSI overpressure relief valve.
WARNING: Be sure the auxiliary
air/gas first stage regulator is fitted with
an overpressure relief valve. A leaky first
stage can overpressure the hose, burst-
ing it and causing a loss of the entire
auxiliary air/gas supply and possible
physical injury to the diver as the hose
whips about. Do not use a high pressure
hose as the system on the helmet is not
designed for high pressure.
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