Gasmizer Manual - Submarine Manufacturing and Products Ltd

March 09
4.5.6 The functions of the diver tracking system components are:
Diver pneumo
To monitor diver depth;
Metering valve 1
To adjust the supply gas to purge the diver
pneumo - a maximum of 0.4 litre/min is
recommended;
Flowmeter 1 Indicates the flow through metering valve 1:
4.5.7 Excessive flow will adversely affect gas recovery figures. Only a very small trickle of
bubbles from the pneumo line should be evident to the diver.
BPR loader
Maintains a constant pressure difference
between diver ambient and BPR setting;
Back Pressure Regulator Controls the exhaust umbilical pressure to be
equal to the BPR loader setting
Metering valve 2
Controls the gas bleed through the BPR loader
to give stable operation. Should be set to 0.5
litre/min;
Flowmeter 2 Records the flow through metering valve 2.
NOTE
Certain types of helmet exhaust valve do not require the use of the Diver Tracking System.
4.6 Bell External Equipment
4.6.1 A check valve and water trap (see Drg. 812149) are mounted externally to the bell. The
purpose of the check valve is to prevent reverse flow of gas from the umbilical into the bell
equipment for example when the bell is being depressurised. The external water trap simply
collects any additional free water, which is either carried over through the main water trap or
condenses in the main umbilical exhaust hose. Little water is anticipated at this point so it is
sufficient that it should be drained at infrequent intervals when the bell is on surface.
4.7 Bell Equipment Maintenance
4.7.1 The bell equipment requires only a limited amount of maintenance, which may be
carried out at a convenient time when the bell is on surface and depressurised.
4.7.2 A maintenance schedule is shown on the following page. Note in addition the following:
1. The bell internal water trap may be drained as required, during a dive, without interrupting
gas recovery.
2. The bell external water trap should be drained EACH DIVE, BEFORE LEAVING
SURFACE.
3. Over a period of time the acrylic housing of the bell internal water trap and the flow
meters will become discoloured. This may be removed by washing in water with
detergent.
OM002 Rev 5 Page 28 of 168 Chap 4