SCBA Operations & Maintenance

Course Aims

SCBA Operations & Maintenance Aims to provide knowledge, understanding and skill for competence in:

• Basic use and testing of self-contained breathing apparatus (SCBA)
• Repair and maintenance of the self-contained breathing apparatus (SCBA)
• Charging of BA Bottles following laid down procedure
• Basic maintenance and upkeep of BA Bottle Charging Compressor
• Air quality upkeep of BA Bottles

Delegates go through Practical on repair and maintenance of the Breathing Apparatus and Charging of the Air Bottles and Compressor routines.

SCBA Components

Main Parts:

• Face Mask
• Back plate
• Cylinder
• Components: Back plate
• Reducing valve
• Whistle
• Pressure gauge
• Harness
• Face mask
• Lung demand valve

Cylinder:

• Weight : 9 kgs
• Working pressure : 300 bar
• Nominal Working time : 50 mins
• Safe (escape) time : 10 mins (0-50 bars) for whistle to blow
• Filling capacity : 9 ltrs
• Face Mask – Open Circuit
• Exhales outside the mask, into the atmosphere
• No re-cycling of air is done

Problems with the face mask:

• Facial Hair
• Corrective Spectacles
• Psychological Disturbances
• Miscellaneous Sealing Problems

SCBA Key Features:

• Positive pressure system
• Open circuit
• Demand valve
• Pressure reducer

Using SCBA:

• Visually check for obvious damage
• Extend shoulder straps and waist belt fully
• Lift set over one arm and shoulder
• Draw to body with other arm
• Place face mask neck strap over head and secure
• Fasten waist belt around body
• Secure with set sitting comfortably on hips
• Pull shoulder straps until comfortable over shoulders
• Re-set lung demand valve by pushing lever forward

Donning SCBA:

• Place harness over head
• Position mask over face
• Pull lower two straps straight back
• Pull middle two straps straight back
• Pull top strap straight back
• Secure mask to face

SCBA Testing:

SCBA high pressure test:

• Slowly open air cylinder valve
• Raise pressure to maximum
• Close cylinder valve
• Listen for air leaks
• Air pressure must not drop more than 10 bar in 1 minute
• If air pressure gauge drops more than 10 bar in 1 minute leak in present
• If leak cannot be remedied set not to be used

Whistle warning unit test:

• Remove demand valve from face mask
• Cover demand valve outlet with palm of hand
• Press centre of rubber cover
• Release pressure slowly
• When whistle emits audible warning
• Note air pressure on gauge
• Audible whistle warning air pressure 50 bar +/- 5 bar
• Replace air cylinder with fully charged unit

Face mask seal test ( Low pressure test):

• Breath normally with air valve open
• Close air cylinder valve
• Continue to breath normally
• Note air pressure when whistle activates
• Face mask will collapse onto face
• Open air cylinder valve
• Inhale 3-4 times
• Listen for leaks
• Depress rubber cone to check supplementary supply

SCBA High Pressure Compressor Routines before starting:

• Check Oil level
• Put air inlet hose in fresh air
• Drain waste oil and water by starting the compressor
• Once all oil and water drained, close the drain valve to drive air to the BA bottle
• Keep bottle in bucket full of water to let the bottle cool down during charging

An SCBA maintenance is not a simple task. It requires a detailed inspection of all the parts and components of the apparatus, as well as a series of functional tests. Hence it is prudent for the people involved in using SCBA to go through SCBA Operations and Maintenance training.