MSA G1 SCBA - Testing the Negative Pressure Seal

37
Donning
G1 SCBA 2018 Edition
US
6.4.1 Testing the Negative Pressure Seal
WARNING!
 If the facepiece does not hold a negative pressure seal, remove the SCBA from service and return
it to an MSA trained and certified repair technician.
 Do a negative pressure seal test before each use and before going into a toxic atmosphere.
Failure to obey these warnings can result in serious personal injury or death.
To make sure the face-to-facepiece tightness is correct, do a negative-pressure seal test before each
use.
(5) Adjust the facepiece.
(6) Tighten the straps firmly and evenly.
(1) Use the palm of your hand or attach the regulator to seal
the inlet connector.
If the regulator is aligned correctly, the bypass knob will be
on the right side of the facepiece.
(2) Test the facepiece tightness.
a) Inhale and hold your breath for 10 seconds. Make sure
the facepiece stays collapsed on the face.
b) Exhale. Make sure the exhalation valve opens and the
pressure inside the facepiece is released.
(3) If necessary, tighten the straps.