Is it safe ?

[rafal1676]

Hi I have a question. recently I bought Worthington X8-130 tank With Thermo pro valve 200Bar 3442psi. Today i went to LDS to fill this tank with nitrox, and they did it . However gentlemen who was doing this procedure told me that he fill my tank to 4100 psi I was surprise because I knew that valve and tank operating pressure is 3400psi. I did ask him about that. He told me that he has same tanks and he puts up to 4800 psi in it. So my question is, is it safe to 4100 psi in my tank or should I drain some of air from them.Thank You Rafal.

 

[Stu S.]

If you have a yoke first stage on your regulator, it is possible that the o-ring in the valve may fail at that pressure. In the whole setup, that's probably the weakest item. If he filled it hot, you may not have 4100 psi in it now. If it was mine I'd check to see how much pressure is in it presently, and lower the pressure to around 3,600 (if you have the yoke setup).

Running that high a pressure with the little o-ring has given us a few failures, typically when we first hook things up. This can be a pain in the neck on boats. And, it's not real good for the tank to do that too often, either.

Take a look at a DIN regulator if you haven't already. We converted our family regs to that as it is more robust.

 

[Dr Wu]

Ask Dustin Hoffman.

Or Max Von...

Either way stock up on Oil of Cloves.

You are gonna need it.

 

[rafal1676]

Thank you for response.I did check preasure after one hour, and on my SPG i have 4100 psi. I have yoke connection, and its true that i I had problem with leaking air on connection where is o-ring.

 

[JKPAO]

Dr Wu, right were I was going when I read It! I may be dating ourselves.

See you topside! John

 

[halocline]

Sure wish I had that problem at my LDS. Quit gloating, would you?

Seriously, 4100 is a pretty bold fill; test pressure for that tank is around 5100. If you're going to dive soon, I would just enjoy the overfill. If it's going to be sitting around, I honestly don't know how much extra stress you're putting on the tank, it's gotta be some, but I doubt if anyone could tell you whether it would affect the longevity of the tank. I think repeated overfills might be more stressful than one that sat full for a while, but I'm guessing.

 

[h90]

4100 sounds a lot...
I would reduce it to 3800.

 

[Scared Silly]

Seriously, 4100 is a pretty bold fill; test pressure for that tank is around 5100. ... I honestly don't know how much extra stress you're putting on the tank, it's gotta be some, but I doubt if anyone could tell you whether it would affect the longevity of the tank. I think repeated overfills might be more stressful than one that sat full for a while, but I'm guessing.

Yeah, there is extra stress but it is not in the range for elastic deformation. Which as I just posted that is what the hydro test looks for elastic deformation.

If the cylinder is well maintained I would not worry about it.