filling 72's

I didn't realize there were concerns with filling LP72's to the standard NFL cave fill- 3600psi... that being said, do you know which shops will or won't fill past the indicated working pressure? Also what are some of the most recent documentations of LP72's exploding if this seems to be the concern. I tried to have them filled today without luck and the concern seems to be thinner sidewalls with this age of tank. I wasn't aware of these issues till now... can anyone fill me in? I didn't find any threads on this forum after searching...

-Matt

Hey Matt!

Are you talking about the old school 2250+ steels?

Safe diving,

Rich

both actually... I have a couple of each

Some 72 sized tanks have a fill pressure of 1800 psi. Be careful! I don't fill mine over 2900, ever.

I have old ones, from the 1970"s. I only fill to 2400psi. I just don't feel comfortable over filling something that old. If I need more gas I just use a larger tanks.

Weak necks. 2400psi max.

I have an old 72 from my uncle that dates to the late 1960's. He had it filled for years down in the West Palm area but after Frank's dive shop closed he could no longer find a place to fill it.
He gave it to me and I brought it up to my home in the north Florida area where we had it fully inspected -- hydro and VIP -- and it passed with no problems and I've been filling it ever since with no issues.
I try to keep it at or under 2500 psi.

Ironically I filled my sidemount 72s yesterday,and the fill person asked me about the pressure,but normally I will sit with those tanks until I know they are aware they are 72s,and no higher than 2400.

I've been filling mine (1972 and a 1973, 2250+) to 3000 on a regular basis for years....maybe I'll back off! I did get a fill to 3600 in cave country once by mistake (filling several different tanks and I got to talking, not paying attention...). I draned them down to 3000 before leaving the shop.

-skip

I like mine to be at 3k...makes math real easy to use it as a stage, and gives me slightly more gas than an 80.

But, I fill slow and don't do the whole "overfill then let it cool" thing. And, I try not to let it sit for forever at 3k before I use it.

I do have to tell fill guys that it's a 72 though, on busy days, they sometimes lose track.