Ensure oxygen pressure is above 165 bars
Plug the T- piece connection with a T- piece connection cap
Hold body Guard in hand
Open oxygen cylinder valve fully and half turn back
Inflate the breathing bag by pressing the manual by passing valve until the pressure plate activated the relief valve
Close the oxygen cylinder valve
Observe oxygen pressure drop to 55 bars or below
Plug the small hole on the T- piece connection with a thumb
Observe the gap between the relief valve and the pressure plate for 60 seconds
If there is no gap between the relief valve and the pressure plate
Meaning there is no leak in the lower circuit, the test has passed
Remove the T - piece connection cap from the T - piece connection to release pressure from the system
Switch off the body guard