- A reducing valve is connected after the cylinders to reduce the pressure to approximately about 4 bars. This pressure is further reduced by the demand valve, which is attached to the mask of the wearer.
- The demand valve supplies air to the wearer when he inhales and closes when he exhales.
- An Exhalation valve releases the exhaled air from the facemask.
- When approximately 10 minutes of air is left (air cylinder pressure about 60 bar), a warning whistle will sound continuously – warning the user that his air supply would soon be over and he has to move out.
- This warning signal will sound continuously till the air in the cylinder is over.
- The facemask is made of moulded rubber with a series of adjustable rubber straps to secure it to the head of the wearer and fitted with quick release arrangements.
- The user should have a good field of vision so that the wearer does not need to turn his head constantly.
- A gauge is provided to indicate the pressure of the air in the cylinder.
- Spare cylinders should be provided for each set of breathing apparatus and a small air compressor to charge these cylinders is provided.
An approximate Consumption and duration table:
