Pressure rises after you stop breathing on reg.

[clownfishsydney]

Okay, I was (stupidly) thinking it was a change of 50-60 bar, not psi. This is a change of 3-4 bar, hardly worth worrying about really.

 

[Manatee Diver]

Okay, I was (stupidly) thinking it was a change of 50-60 bar, not psi. This is a change of 3-4 bar, hardly worth worrying about really.

I'm just curious what is causing it, as it seems weird to see the pressure rise.

 

[J-Vo]

I switch every 300psi or so, and see 20 to 50 psi rise on the side I just quit breathing as normal for my LP85s. I expect it's a temperature thing as discussed above.

 

[Jay Adams]

Broncobowsher has the correct answer, the valve is not fully open or there is a problem with it so that it is not fully open although the handle might be open. The correct symptom is not that the pressure rises after you stop breathing on the regulator, more that it drops when you breath. Have seen this many times. At depth and when a tank is fairly well used, a person will think they have no air left.

My experience with this as well. I took my 14 year old daughter in the water to try diving, and her spg kept going from 3000 psi down to 100 psi, each time she would breath in... I called the dive to find out she hadn't completely opened her valve...