Converting LP 72's to doubles

[zider]

I wouldn't mind a bit more info on bands.

My LDS is selling off 6 steel 72s cheap, and it crossed my mind to buy a pair and convert them into doubles. My initial problem was that the cheapest manifolds that I found (by miles) were XS Scuba, but nobody seems to offer bands specified for them. It never actually occurred to me that I might have to separately consider the diameter of the tanks as well. Surely there must be some standardisation of bands? It can't be that everyone orders custom?

Certainly welcome any advice/suggestions.

You can get 6.9 inch bands for 72s from these guys
Piranha Dive Manufacturing

 

[PR_SMITH]

You can get 6.9 inch bands for 72s from these guys
Piranha Dive Manufacturing

and here, too

Stainless Steel Double Tank Bands

 

[superspeed]

49 CFR section 173.302a(b) allows for tanks stamped with the "+" to be overfilled 10% EVEN IF THE TANK DID NOT GET A "+" STAMP ON SUBSEQUENT HYDROSTATIC TESTING. If the "+" was originally stamped on the tank, it can be overfilled by 10% so long as the tank's vis and hydro are current.

Tell Ocean Concepts to look up that regulation, and you should be able to still get your tanks overfilled 10%. Or move to another dive shop.

 

[WD8CDH]

49 CFR section 173.302a(b) allows for tanks stamped with the "+" to be overfilled 10% EVEN IF THE TANK DID NOT GET A "+" STAMP ON SUBSEQUENT HYDROSTATIC TESTING. If the "+" was originally stamped on the tank, it can be overfilled by 10% so long as the tank's vis and hydro are current.

Tell Ocean Concepts to look up that regulation, and you should be able to still get your tanks overfilled 10%. Or move to another dive shop.

That's not entirely true. Per the rest of that section of code, the maximum wall stress must be determined on each hydro that the "+" is applied to. And the "+" must be on the current hydro for the 10% overfill to be allowed. See especially 49 CFR section 173.302a(b)(5)

A 3AA tank doesn't need the "+" on all of the hydros, but it MUST be on the current hydro for the 10% overfill.

 

[oxyhacker]

Exactly. The only "+" that counts is a current one. If you call the DOT phone hotline they may tell you otherwise, but you really shouldn't call the DOT phone hotline about anything important.

BTW, there is no point in getting too hung up on the plus since most hydro shops simply do not have a clue how to do it for 72s and no amount of talking or arguing is going to confer on them the ability to. Also, and probably more to the point, most dive shops don't seem to make any distinction anyhow when filling - when I get my 72s filled they almost always end up with 2400-2500 in them, regardless of whether they are "+" rated or not.

Oh and 72s do make lovely doubles, great for learning and rough water. Much nicer than a single huge tank.

A 3AA tank doesn't need the "+" on all of the hydros, but it MUST be on the current hydro for the 10% overfill.

 

[WD8CDH]

Also, and probably more to the point, most dive shops don't seem to make any distinction anyhow when filling - when I get my 72s filled they almost always end up with 2400-2500 in them, regardless of whether they are "+" rated or not.
QUOTE]
And it they are the same color as the shop's rental tanks, they usually end up with 3000psi in them.

 

[diver 85]

Sell them & get you a hp100 or 120......