8-8 Change A
U.S. Navy Diving Manual—Volume 2
diver’s harness before entering the work space so that the diver has immediate
access to the EGS regulator in an emergency.
An adequately charged scuba cylinder is defined as the pressure that provides
sufficient air to bring the diver to his first decompression stop or the surface for
no-decompression dives. It is assumed that this will give topside personnel enough
time to perform required emergency procedures to restore umbilical air to the
diver. See paragraph 8-2.2.1 for calculating minimum cylinder pressure.
8-3.2.2
EGS Requirements for MK 20 MOD 0 Open Water Diving. When conducting open
water dives, the diving supervisor may use a MK 20 designated ANU approved
cylinder with the DSI sideblock assembly as an emergency air source.
8-3.2.3
Flow Requirements. The MK 20 MOD 0 requires a breathing gas flow of 1.4
acfm and an overbottom pressure of 90 psig. Flow and pressure requirement calcu-
lations are identical to those for the MK 21 MOD 1 (see paragraph 8-2.2.3).
8-4
EXO BR MS
8-4.1
EXO BR MS. The EXO BR MS is a commercial-off-the-self, full face mask,
manufactured by Kirby Morgan Dive Systems, which can be used for either
SCUBA or surface supplied diving. It is authorized for use to 190 fsw with air and
140 fsw with nitrox. An Emergency Gas Supply (EGS) is mandatory at depths
deeper than 60 fsw and when diving inside an enclosed space. The Diving Super-
visor may elect to use an EGS that can be man-carried or located outside the
enclosed space and connected to the diver with a 50-150 foot whip. Conducting air
dives below 190 fsw requires CNO approval.
8-4.2
Operations and Maintenance. The technical manual for the EXO BR MS is the
Kirby Morgan Operations & Maintenance Manual, EXO BR MS Balanced Regu-
lator Full Face Mask Military Standard (DSI Part #100-036). To ensure safe and
reliable service, the EXO BR MS must be maintained and repaired in accordance
with PMS procedures and the technical manual.
8-4.3
Air Supply. For surface supplied diving, air for the EXO BR MS is supplied from
the surface by either an air compressor or a bank of high-pressure flasks as
described in paragraph 8-6.2.3.
8-4.4
EGS Requirements for EXO BR MS. The EGS system consists of adequately
charged ANU approved cylinder with either a K- or J- valve and an approved first
stage regulator set at manufacturer's recommended pressure but no lower than 135
psi over bottom pressure. The intermediate hose of the first stage is coupled to the
emergency gas supply valve on the manifold block assembly. A relief valve set at
180 +/-5 psi over bottom pressure must be installed on the first stage regulator to
prevent rupture of the low pressure hose should the first stage regulator fail. The
flexible low pressure hose from the first stage regulator attaches to the emergency
supply valve on the manifold block. A submersible pressure gauge is also required
on the first stage regulator.
