Very strange unexplained air loss

[SmokeAire]

I had a very strange situation last Fri. concerning my two tanks.
I have two steel LP95s with DiveRite H-valves. Last Tues. I had the tanks filled to about 3300psi. The tanks were in my CRV all week. Fri. morning I decided to load my gear into my car for Sat. Venice Beach dive. When I opened up the back of the car I noticed that my tanks were sopping wet with condensation. I felt the tanks and they were ice cold. I figured that the only way the tanks could be in that condition was for the air to escape very quickly. Blown burst disc maybe? I hooked up my spg to the tanks. This is the very strange part, one tank had 1000 lbs and the other had 2000 lbs. They still had air. The fact that the tanks were still very cold indicates that the air loss happened within the last hour but I didn't hear a thing.
I took the tanks down to my LDS, we took the valves apart, everything seemed fine. Did a VIP on the tanks and there was some moisture in them so we dried the tanks and reattached the valves, filled the tanks and layed them down in the water bath. No leaks.
Now I can't imagine that some person would have gotten into my car, open the valves just long enough to let some of the air out at great velocity and noise and then close the valves.

Any thoughts as to this mysterious air loss?

Chuck

 

[OneBrightGator]

Maybe they moved around and the valve got opened slightly? I've had that happen before with my doubles in the back of my truck.

Ben

 

[whalerkyle]

It was the one armed man!!

Ive had one of my tanks go full open in the back of my car once, and then stopped around 800 psi. I could never figure out why.

Kyle

 

[SmokeAire]

Both valves were closed when I checked and to have this happen to both tanks at exactly the same time is a bit weird. Plus I made covers for the valve knobs that keep the knobs from being accidently turned on so if someone did do this the covers would have to removed...all four covers were still on the knobs.
The question is why would one tank lose 1300 lbs and the other 2300 lbs and then stop leaking? And this wasn't a slow leak over a period of days it was an explosive leak that left the tanks dripping wet and ice cold. Curious.

 

[Uncle Pug]

Plus I made covers for the valve knobs that keep the knobs from being accidently turned on so if someone did do this the covers would have to removed...all four covers were still on the knobs.

This kinda makes the one armed man less likely though that would have been my first guess too...

Well then... it must have been the trunk monkey!

 

[Ontario Diver]

A couple of options....

1) the valve got whacked/bumped/knocked/too hot and the seat/valve stem/burst disk assembly/neck o-ring cranked open just enough to let some air out. When the air got down to "less" pressure, the system was able to reseal.

2) Thanks for letting me borrow your tanks for the ice dive.


Personally, I'd guess some variant of #1. I'd check the valve seat and the burst disk assembly.

 

[SmokeAire]

Well then... it must have been the trunk monkey!

LOL...actually I did have an incident involving two trunk doggies.
I have a Honda CRV and I usually keep the back seats folded flat.
One day I had my two tanks and my two dogs in the car and I was driving down the road going about 45 or so. One of my dogs must have step on valve knob. Well let me tell you that was an underwear staining experience. I had dogs flying into the front seat trying to get into my lap or out of the car altogether, my heart had jumped into my throat and I'm trying to find a place to pull over. That was the reason I made the knob covers. Plus it keeps uninformed DMs from turning my air off when they think they are turning them on which has also happened.

 

[SmokeAire]

A couple of options....

1) the valve got whacked/bumped/knocked/too hot and the seat/valve stem/burst disk assembly/neck o-ring cranked open just enough to let some air out. When the air got down to "less" pressure, the system was able to reseal.

2) Thanks for letting me borrow your tanks for the ice dive.


Personally, I'd guess some variant of #1. I'd check the valve seat and the burst disk assembly.

I think that (#1) was kinda the explantation that my LDS gave me...but again both tanks at the same time?

(#2) You're welcome....how did you come down here...on the Concord?

 

[herman]

Not sure why you lost air but the condensation was most likely just due to overnight cooling. The tanks take a long time to cool or heat up with reference to the vehicle temp so a cold tank in a quickly warming car interior will sweat. This is esp true if you have them covered with something. I had mine in my SUV last weekend and they were very cold and completely covered in sweat at about noon on Sat. The night time temp was around 45 and the temp in the car was in the mid 70's to low 80s. I have seen this a lot of times.

 

[Henryville]

I think Herman is right, you are assuming it all happened at once but as you say that seems pretty far fetched. Being they were in your car for a week, maybe they heated up, that was enough pressure to sneak by a ring or a valve that wasn't totally tight, they leaked off until they resealed (slow leak.) Then there just happened to be condensate the morning you went to use them.

Like Sherlock, look for the dog that didn't bark!