scubafanatic
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When diving a yoke style 1st stage, and practicing and out-of-air emergency drill, what happens to the 'air-tightness' of the O-ring seal between the tank valve and the 1st-stage-inlet-port?
The reason I ask is it's common during training for instructors turn off a student's air supply to experience an OOA emergency, yet at the same time divers are warned how important it is to 'barely' tighten (2 fingers tight) the 1st stage yoke screw, as the air-pressure from the tank --when the tank is turned on--will 'inflate' the O-ring, bridge/seal the 'gap' and form a tight seal so water won't enter the 1st stage.
What hasn't been addressed is what happens to the 'quality' of this 'seal' when the air-pressure falls to 'zero' as the air is turned off.......will the O-ring spring a leak, allowing water into the 1st stage?
Is the 'solution' to tighten the yoke screw a bit more tightly than the recommended '2-finger-tight' level to compensate for the absence of air-pressure maintaining the o-ring seal?
Karl
The reason I ask is it's common during training for instructors turn off a student's air supply to experience an OOA emergency, yet at the same time divers are warned how important it is to 'barely' tighten (2 fingers tight) the 1st stage yoke screw, as the air-pressure from the tank --when the tank is turned on--will 'inflate' the O-ring, bridge/seal the 'gap' and form a tight seal so water won't enter the 1st stage.
What hasn't been addressed is what happens to the 'quality' of this 'seal' when the air-pressure falls to 'zero' as the air is turned off.......will the O-ring spring a leak, allowing water into the 1st stage?
Is the 'solution' to tighten the yoke screw a bit more tightly than the recommended '2-finger-tight' level to compensate for the absence of air-pressure maintaining the o-ring seal?
Karl