Steel LP72 2250psi tank spec

[halocline]

If they are PSTs, you can still get the plus rating at some hydro shops (you'll have to find a good one and that will be an adventure all its own) because the PST document with the REE is available. With that rating dive shops are really supposed to go to 2475. Hot fills are everywhere, it seems. At my LDS it seems to depend on who's doing the filling that day, but they've never objected to topping tanks off once they cool down. Try explaining that the service pressure is based on room temp and that it's perfectly acceptable within DOT guidelines to go over a bit when they're hot. (good luck!!)

Another somewhat expensive but do-able solution is to own a higher pressure tank and use it to top off your LP72s with either a transfer hose or 2 first stages connected with a HP hose and a male/female adapter. I have done this on occasion. Don't forget to have a second stage on one of the firsts, or you'll have lots of fun getting them off the tanks.

 

[duckbill]

2200 is close, but 1800 is unacceptable. Spell the word f-i-l-l for them and define it! There's no way that even a 2250 psi hot FILL (there's that word again) cools to 1800 psi. You did pay for a FILL, didn't you? How FULL is a FILL? I'd ask them that, then have them pro-rate me the difference if they don't want to top it off.

 

[Luis H]

Here is some information on steel 72 and tank testing that may be of interest:
Vintage Double Hose • View topic - Vintage tank hydros and "+" stamping

 

[Luis H]

Even though their small, LP 72's are one of my favorite tanks.
I like them for short beach dives diving wet. They also make a sweet set of the cutest little doubles you've ever seen.

Small... this are my big tanks... my small doubles are double 45s and double 50's. Now those are cute. Double 72s is about as big as I ever care to carry.

 

[Ed Palma]

Okay, quick question... are these tanks still being manufactured according to the specs above? If not, why not?

 

[McCainiac]

Same issue with many steel tanks in the bay area - getting a healthy fill can be hard at a lot of dive shops. I do know that at least one local shop that overfills steel tanks will still only fill LP72s to about 2600psi.

I own a set of 72's that are PLUS rated and my LDS will go 500 psi over. I'll never dive a AL80 again.

 

[mictrik]

Thank guys. This is exactly the information I am looking at. I was doing some diving with this tanks over the weekend, so I was very curious about their specs.

My feeling for them is mixed at best. I like how they are less bouyant then AL80 (noticeable), a bit shorter and narrower also. However, I could not get them fill properly, to 2450psi, at two dive shops in the dive site. Twice they filled to 2200psi, and twice they filled to 1800psi only. The 1800 fill was hot fills, the tank felt warm. I think the issue is the operating pressure itself, 2450 is so low, even a few hundred psi under fill, there is a significant reduction at gas capacity. I guess the big question is how to get them overfill by a few hundred PSI in NorCal.

What dive shop under-filled you on a steel 72?? You should tell them straight out that you were short filled as I am sure it was not done on purpose. An 1800 fill is totally unacceptable, especially if your tanks have a "+" beside the hydro stamp. The plus adds 10% to the 2250 working pressure bringing fill pressure to 2475 and getting you just about 72cf of air. Almost all steel 72's were commonly filled between 2500 and 3000 back when they were the main stay tank. I think at 2700 they actually hold more than an alum 80. Before you bring your steel tanks for hydro make sure they will plus the tank; place a note on the tank as a reminder. Get the REE number for your tanks and write it on the note. I find steel 72 cylinders to be great tanks and having them filled to capacity (or slightly more) is rarely a problem.

 

[KY_BOB]

Okay, quick question... are these tanks still being manufactured according to the specs above? If not, why not?

No and beats me.

I have a set of doubles and a single. I love diving both the single and the doubles AS LONG AS I GET A GOOD FILL. One local shop will only fill them to 2250 when I hit the water, I'm lucky to have 2100. Another shop doesn't care to put 2700-2800 in them. I try to only get them filled at the latter of the 2 but it's a bit of a drive to get there.

Those are my fun diving tanks. I have larger for more complicated dives.

 

[oxyhacker]

Not that I know of. The alu 80s pretty well killed the 72s, and when the current crop of LP steels came out, they were 2400 psi tanks. Why is hard to say. But then you can't buy new '57 Chevys or Gravely walking tractors any more, either.

I have heard it said that the steel 72 specs pushed the limits in certain regards, and were of borderline legality under to DOT regs, but I can't recall the details.

Okay, quick question... are these tanks still being manufactured according to the specs above? If not, why not?

 

[Bob DBF]

2200 is close, but 1800 is unacceptable. Spell the word f-i-l-l for them and define it! There's no way that even a 2250 psi hot FILL (there's that word again) cools to 1800 psi. You did pay for a FILL, didn't you? How FULL is a FILL? I'd ask them that, then have them pro-rate me the difference if they don't want to top it off.

I've been logging my tank pressures as I rig up to dive, it's understandable for the pressure to drop when you hit 50 degree water, and read back the results to the fill monkey when having them refilled. I'm now getting great fills on my 2250's and 2400 tanks and the 3000's and 3445 are a lot closer, seems the squeaky wheel gets the grease. I hold one of the employees up as an example because her fills are at the mark or above every time. On the HP fills the heat is the real problem, even in a water bath, so I hang out and let them cool and have them topped off if I need all the air.

Training is the key with SCUBA.

Bob
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