PSI Gauge when breathing

[rx7diver]

5. Turn the valve all the way off again. Breathe it all the way out. Inhale hard, if you get anything at all, you have a wet breathing secondary. Pass on it, ask for another...

Careful: Not too hard. With some regs (e.g., Scubapro Balanced Adjustable), if you inhale too hard (after you've turned the tank valve off, and you've breathed down the air in the hoses), you can unseat the mushroom valve in the second stage—that is, you can suck part of the mushroom valve through the hole it's supposed to seat against. When this happens, you definitely will have a wet-breathing reg. (If this happens, though, simply pull off the exhaust tee, flip the corner of the mushroom valve back out of the hole you just sucked it through, put the exhaust tee back on, and you should be good to go.)

Safe Diving,

rx7diver

 

[Storker]

Just a small point: If the topside temp is below freezing, think twice about those three deep, hard breaths. There's fair chance that that is just what's needed to get your reg freeflowing.

I've experienced - and seen - regulators working perfectly fine both pre-dive (with a little care and concern) and underwater, but freeflowing violently if there's a hard, strong airflow through it while the air surrounding it is significantly below freezing.