Course Aims

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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.

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SCBA Components

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Main Parts:

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

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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

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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

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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

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SCBA Testing:

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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

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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

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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

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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

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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.