Hold body Guard in hand
Plug T - piece connection with a T - piece connection cap
Cover Thuli with I rubber cap
Do not submerge the body Guard in water
Do not submerge the switch box in water
Ensure you have an extra T - piece connection cap
Open the oxygen cylinder valve fully and a half turn back
Block the relief valve with an T - piece connection
Inflate the breathing bag until the pressure plate holds the relief valve in position
Do not submerge the body Guard and switch box in water
Dunk the breathing apparatus in water
Observe bubbles in the lower pressure circuit
Rectify the problem
Redo the positive leak test