Leaky Reg?

[hendenburg2]

So on a recent dive trip, I noticed after I turned opened the tank valve to check to see how much air the boat's crew put in the tank, and then closed the valve, the pressure in my reg setup dropped ~50 PSI per second. On both dives, after a 1-minute paddle out from the boat to the drop line, and then about a 1-minute wait to give other groups clearance in their descents, and then a 1-1.5 minute descent to 90 feet, the pressure in my tank dropped ~500 psi. The wrinkle, however, stems from the fact that the leaking seemed to have slowed/stopped while I was at depth. Any idea why this would happen?

Additional info: When I re-tested the reg at home with my own tank, there was still some pressure drop after shutting off the tank valve, but it did not drop nearly as fast of a rate as on the boat trip

 

[rongoodman]

Did you or your buddy see where the bubbles were coming from while you were in the water?

 

[redacted]

The fairly large drop when you entered the water is probably due to a hot fill quickly cooling to the water temperature.

One of my pre-dive checks is to pressurize my rig and then turn the valve off and watch the SPG. It is not uncommon to see a slow drop. It is often cured by twisting the 1st stage a bit to better seat the yoke o-ring. Occasionally it requires a new o-ring on dive op provides tanks. If that does not work, I always carry a spare regulator set-up if there is not enough time to troubleshoot and repair my rig.

 

[hendenburg2]

yeah the boat had a compressor so they fill re-fill tanks during surface intervals, which I suppose would explain a hot tank on the second dive, but that being said the air temp was mid-60's and it was overcast, but that wouldn't explain the first dive.

I didn't see bubbles, but that only means so much, and I completely forgot to ask my dive buddy.

 

[OkByMe]

Change all the O-rings on the hoses, and check the SPG spool. Should be done every once in a while anyway.

 

[Steve_C]

I had a buddy tell me he saw a slow leak. At home with tank/reg in water I could not see it. Only was able to locate it with a fresh full tank. As soon as the pressure dropped 1000 psi the leak went away. It was in the high pressure line to the SPG.

 

[beanojones]

One reason to be comfortable doing gear R&R underwater is to be able to look at your own gear underwater. Asking someone else to find a leak underwater (especially if they are inexperienced), results in some funny ideas.

 

[gcarter]

Had a tank valve rebuilt recently and an o-ring was not replaced. It caused the tank valve to leak, much like you described, draining the line even with the valve closed. We did not actually dive the tank until it was fixed.