"Cave Fills"

[mk706]

My thoughts are that a tank when hydro'd gets filled to a crazy amount so in theory a cave fill isn't going to hurt your tank and the burst disc will protect the valve

Burst discs are intended to give at a certain pressure so that pressure doesn't have to escape though the side of the tank.

Hydro fills to 5/3 service pressure. Hydro on an LP tank is 4400 psi, 5736 for mid pressure tanks.

 

[kelemvor]

My LP108's (2400) have been routinely filled to the 3500ish range. Haven't changed the discs, so far no broken ones. They'll be due for their first hydro next year I think. Several cave divers including my instructor tells me they've done that to their tanks for years and years with 0 problems.

When I started Day1 of Cave1, they pumped me up to 3900. I was pretty nervous (about the fill), but didn't have a problem.

 

[CuzzA]

This may come across wrong, but at the end of the day it's the guy filling the tank who would be at the highest risk of injury or death from a fill. If it were going to go I would think it would happen at the time of the fill. So considering a lot of shops overfill tanks, clearly they feel comfortable doing it.

 

[The Chairman]

This may come across wrong,

That's the God's honest truth. I never argue or complain with the person filling my tanks. I appreciate every PSI they give me.

 

[kelemvor]

On that note, I wonder what pressure the banks are filled to. If they can pump it up so high so quick, the bank must be awfully high pressure.

 

[mk706]

On that note, I wonder what pressure the banks are filled to. If they can pump it up so high so quick, the bank must be awfully high pressure.

Typically cascading banks are filled to the end-state pressure, be that 3000, 3600 or other pressure.

 

[The Chairman]

I see them closer to 4,000 in Cave Country.

 

[Littlerayray]

The high banks at my lds have a capacity of 4000psi

 

[oya]

Linda Renneker-Strait told me a story one day after asking me "What kind of fill do you want?" and I was all confused by the weird question.

Guy picks up some tanks with a few cavern students and heads off for a dive.
Comes back hours later angry.
"Do you know what these tanks are supposed to be filled to?" he demanded.
"What?" I imagine Linda said, likely not finishing the sentence, "What the hell are you talking about?"
"I had to empty over 1000psi out of these tanks before we used them. They were filled to over 3500psi. These are low pressure tanks!"
"What?" Linda said was all she could squeak out without laughing.
"Just be more careful next time!"
"OK."

Linda said for a few months afterwards she asked everybody what kind of fill they wanted.

 

[The Chairman]

Linda's a sweetheart. But it's another case of never let a good deed go unpunished.