SELF-CONTAINED BREATHING APPARATUS (CTS-IB-PPE-01)
©Chlorine Tech Services (Pty) Ltd
–
CIPC Reg # 2018/101848/07
Rev # 01/2020/10/15
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2.2.
Workings of the SCBA
2.2.1.
The cylinders contain about 1240 litres of compressed air at 300 bar. This gives the
wearer around 30 minutes of air supply for full usage or about 20 minutes for working
conditions (person breathes heavily during work hence there is more consumption of air
and that is why the time is lesser).
2.2.2.
The reducing valve reduces the pressure by about 4 bars which is further reduced by the
demand valve which is attached to the mask.
2.2.3.
The demand valve is the one that supplies the air to the wearer when inhaling.
2.2.4.
The exhalation valve releases the air from the facemask.
2.2.5.
When the air left inside the apparatus will last about 10 minutes (50-55 bar pressure), a
warning whistle is sounded continuously till the cylinder gets emptied. The start of this
whistle is an indication for the
wearer to move out of the space he’s in to fight fire or
whatever purpose it is used for.
2.2.6.
The face mask is of soft moulded nature rubber and five adjustable head straps
and a neck strap. It has a foam filled or air cushion seal and a full vision visor.
For correct positioning of the mask, the straps should be tightened in the
sequence where the first two lower (chin) straps then the middle pair (cheek
straps) and finally the head strap is tightened. Care should be taken to not over
tighten them causing discomfort to the wearer. The mask is made of rubber and
plastic with a shatterproof visor. It has an exhalation port with a speech
diaphragm and a nose guard.
2.2.7.
The wearer should have a good, clear field of vision through the visor.
2.2.8.
A gauge is provided, clipped or attached to the harness that carries the cylinder
and it monitors the pressure within the cylinder. It is positioned to be visible to the
wearer.
2.2.9.
Spare cylinders must be provided for each set of breathing apparatus.
2.2.10.
In case that the facemask is dislodged in a toxic atmosphere, the wearer should
hold his breath and position the mask correctly. Any inlet of such toxic air can be
highly dangerous.
Fig. 1
