Chapter 2
Cylinder and Components
Edition 1 – December 2019
SAFETY FIRS T
27
MSA G1 Classic Breathing Apparatus
Mechanical low pressure warning whistle
The mechanical low-pressure warning whistle is located at the pressure reducer next to
the cylinder connection valve. It is an acoustic warning device (signal/whistle) that
triggers a continues 95 dB warning whistle.
Figure 15
– mechanical low pressure warning whistle
The low pressure warning whistle is low pressure activated and low pressure operated
to trigger the continuous warning signal when the cylinder pressure drops below
55 +/- 5 bar.
Activation of the low-pressure warning whistle indicates to the operator that they have
approximately six minutes of breathable air remaining at 60 lpm.
When in operation, the low pressure warning whistle uses 5 lpm of air, which has a
negligible effect on the working duration of the cylinder.
At 55 +/-5 bar the heads up display (HUD) pressure lights change to one illuminated
continuous flashing red light and all buddy lights begin to continuously flash red. The
electronic low pressure warning alarm continues to operate in parallel with the
mechanical low pressure warning whistle.
This whistle continues to operate even when the set has no power.
