Ominous tanks leak?? Help

[ermaclob]

this has been happening on my doubles. For some time know ive been noticing that the psi on my tanks the day of the dive has been significantly lower then what i though it should be. At first i though that it was because they where steel and not to many shops her in Miami have fill buckets or fill double steels, so i assumes it was because of rapid filling and no cooling. i i started going to a better shop with good filling practices and still lower psi on the day of the dive (tho not as bad)....

Ok so i get the tanks filled to do a test. i fill them to service pressure let them cool of properly then top off. both post read ~2700 psi (manifold is open) i take them home and put them in there storage spot close the manifold and wait. 6 days later.... left tank ~2700 psi right tank 1700 psi ...... wtf????!!!

ive put my ears all over the tanks and valves, sprayed soupy water on the valves and neck of tanks to find leaks.... nothing....

how can i ID the issue?? any one have some advice on how to find the leak? i dont just wana take the manifold to the dive shop and have them service it with out singling out the problem first. i have an OMS manifold not double o-ring

i think im throw the tanks in the pool and see if there are any bubbles coming out of it.

one thing i was wondering the tank that has lost the air was the one that i used to fill the tanks (only one fill whip). is it possible that after closing the manifold only that tank experienced psi loss? i dought it really but

 

[herman]

Sounds like a slow leak. Put submerge them (bath tub will do) and look for leaks, most likely the tank O ring or a burst disk. A leak that is just a bubble every few seconds can not be heard and soapy water is not likely to find it either but over a few days will give you that amount of pressure loss.

 

[spectrum]

Check the pressure 4 hours after fill and store at a fairly stable temperature, then recheck in a few days. If there is no change then it;'s still just cooling. If there is a drop a leak. A bubble check in the meantime would be easy too.

Unless you leave them to cool and they do a very gentle top-off there will be pressure drop. If they will overshoot you can land at the right pressure when cool.

The fact that it improved with a change of shops suggests that your rig is OK.

Pete

 

[kotik]

Check the pressure 4 hours after fill and store at a fairly stable temperature, then recheck in a few days. If there is no change then it;'s still just cooling. If there is a drop a leak. A bubble check in the meantime would be easy too.

Unless you leave them to cool and they do a very gentle top-off there will be pressure drop. If they will overshoot you can land at the right pressure when cool.

The fact that it improved with a change of shops suggests that your rig is OK.

Pete

The OP checked the pressure when the isolator was open, then closed it, and checked pressure later on the individual tanks-- one was at the original pressure, one had dropped 1,000 psi. So that has to be a leak, either at the manifold o-ring on that side or somewhere on the valve or tank neck. Anyway, I can't imagine anyone giving a fill that would result in a thousand psi drop due to cooling-- if nothing else they would slow down their fills once they burn their hand touching the tanks afterward...

ermaclob, I bet you will find something when you do the bubble check.

 

[PfcAJ]

I vote for a bad valve seat. Have the manifold rebuilt.

 

[spectrum]

The OP checked the pressure when the isolator was open, then closed it, and checked pressure later on the individual tanks-- one was at the original pressure, one had dropped 1,000 psi. So that has to be a leak, either at the manifold o-ring on that side or somewhere on the valve or tank neck. Anyway, I can't imagine anyone giving a fill that would result in a thousand psi drop due to cooling-- if nothing else they would slow down their fills once they burn their hand touching the tanks afterward...

I missed that detail and stand corrected, so much for breakfast while posting!

Pete

 

[ermaclob]

this is the problem..... whats the best course of action?... just take that section to the dive shop.

Doubles Manifold Leak - YouTube


[video=youtube_share;J7r7KmyA_UM]http://youtu.be/J7r7KmyA_UM[/video]

 

[kotik]

I think they ought to be able to service the valve with everything still assembled. The best bet would probably be to check with your shop before going to the trouble of breaking it all apart.

 

[Rich Keller]

Soaking it to check for leaks is the easiest thing you can do. There could also be a problem with the burst disk.

 

[Jim Lapenta]

If it were me, rather than playing around with it I'd just empty the tanks, take em apart, and service the entire manifold including the valves. Cause sure as heck you'll rebuild the isolator, put them back together, and then one of the valves will crap itself. It's not expensive to do the whole thing and a competent tech could do all of them in an hour or less. Valves are easy. And you'd have the peace of mind that comes from knowing that it's all new.