Mystery tanks

[trevorrowe]

I recently purchased 2 tanks (got them cheap). Unfortunately I have been unable to identify the volumes of the two tanks. I do know they are both steel tanks. Here is a photo with 2 other tanks included for size reference:

From left to right:

Steel HP 100 (3440 PSI)
Unknown blue tank
Unknown skinny tank
Luxfer Aluminum 80 (3300 PSI)



I took a lot of close up pictures and added some notes to them. You can view them in a set I made on flickr: http://www.flickr.com/photos/trevorrowe ... 486961118/

Here is what I've been able to tell from the markings (the blue tank is much easier to read):

Blue Tank:

DOT-3AA2400
A645568 c
GALV
6 * 93+

I'm guessing the first line shows its a 2400 working pressure. The A645568 c (the c is in a diamond) is probably a serial number. GALV ~ galvanized and the 6 * 93+ is an old hydro stamp.

Skinny steel tank:

U.S. Diver
1CC3AA22?0 (22x0 PSI ? low pressure)
K72402 (serial?)
USD 67+

I believe the original hydro test was done on this tank in 1967!
(click thumb for a larger img)

Anyway, I'm stumped. I can only guess what size they are. I just had them hydro'd. They both passed, but the guy at the LDS was completely useless in getting information about the tanks. He was so miss-informed it hurt. Thoughts? Anyone reconize these tanks?

[E_Mo]

Hopefully this link will help; http://www.scottecatalog.com/scotttec.n ... enDocument

Unfortunately it doesn't say how to get the tank size from the information, but it does verify that A645568 c is the serial number and "GALV" is the company's identification code, which is on file with DOT.

I'm sure if you can get the company's name from DOT and give the company the identifying information they will be able to tell you the size of the tank.

[spatman]

i don't honestly know if these specs will apply to older tanks, but here's a chart of measurements you might be able to apply:

http://www.huronscuba.com/equipment/scu ... ation.html

[Dmitchell]

The silver one is a Steel 72CF 2250psi. I would guess the blue is a LP 80 probably a Faber.


On the blue one the diamond symbol designates the manufacturer. I have the list at my shop but not at home. If nobody answers it for you I'll get it tomorrow. GALV means that tank is GALVANIZED!

Dave

[CaptnJack]

"Galv" just means galvanized, that's not a company

The blue one, is odd, its 7 or 7.25" diameter and was apparently made by Coyne (C inside the diamond).

Its been repainted. Its a lp tank (2400+10% = 2640psi). Based on the size, about 21" tall right - not counting the valve? I am guessing that its about 66cf capacity. To be an lp80 it would have to be taller - closer to the hp100 height and definitely 7.25" diameter. Better dimensions would help this ID more conclusively.

The taller skinny one is a steel 72, 65cf @ 2250psi, 72cf @ 2400. Probably made by PST for US divers. It may have an epoxy liner which sucks but can be blasted out by fire king for a fee.

[dsteding]

The silver one is a Steel 72CF 2250psi. I would guess the blue is a LP 80 probably a Faber.


On the blue one the diamond symbol designates the manufacturer. I have the list at my shop but not at home. If nobody answers it for you I'll get it tomorrow. GALV means that tank is GALVANIZED!

Dave

Isn't the C in the diamond for Coyne or something like that?

HEY RICHARD!

[edit-never mind]

[Dmitchell]

BTW, You needs to take that blue one back to the Hydro shop and get them the retest it with a + mark or else it's only supposed to be filled to 2400 instead of 2640.

[Dmitchell]

I don't think its been repainted. I had a yellow LP 95 for awhile that was just like it. all it said was GALV and the Diamond symbol.

[CaptnJack]

I don't think its been repainted. I had a yellow LP 95 for awhile that was just like it. all it said was GALV and the Diamond symbol.

If that's true, its never been wet since it was made in 93. That blue paint is (comparatively) immaculate

[Dmitchell]

That wouldn't surprise me either. Someone brought me a Scubapro MK5 - Balanced adjustable today that is almost brand new!

[trevorrowe]

I've got some more information. I went and measured the blue tank:

Blue tank:

Circumference: 23"
External Diameter: ~7.3"
Height: 21"

Skinny tank:

Circumference: 21.75"
External Diameter: ~6.9
Height: 24"

I I've added some marking on the pictures that show where I took my measurements. If it would help I could drop them on my bathroom scale to get an approximate weight (they are both filled).

[trevorrowe]

i don't honestly know if these specs will apply to older tanks, but here's a chart of measurements you might be able to apply:

http://www.huronscuba.com/equipment/scu ... ation.html

I couldn't find anything that was a solid match, I'm guessing because they are older tanks and different manufacturers.

[trevorrowe]

The blue one, is odd, its 7 or 7.25" diameter and was apparently made by Coyne (C inside the diamond).

Based on a 23" circumference and 2 * PI * R = circumference that would mean that DIAM = 23 / 3.14159, which comes out to 7.32" - and yes, 21" tall.

The taller skinny one is a steel 72, 65cf @ 2250psi, 72cf @ 2400. Probably made by PST for US divers. It may have an epoxy liner which sucks but can be blasted out by fire king for a fee.

How would I know if there is (still?) an epoxy liner and what does that mean for me?

[trevorrowe]

BTW, You needs to take that blue one back to the Hydro shop and get them the retest it with a + mark or else it's only supposed to be filled to 2400 instead of 2640.

Yeah, so thats an interesting point. I dropped the tanks off a "nameless local dive shop" and instructed them to hydro the two tanks for me. I specifically requested the tanks be + rated. I don't know all that much about tanks yet, but my understanding is they can plus a tank which says, "go ahead and overfill by 10%"... well both tanks came back, neither were + rated. I know they both have been so previously, you can see so in these two images:

http://www.flickr.com/photos/trevorrowe ... 486961118/
http://www.flickr.com/photos/trevorrowe ... 486961118/

When I asked at pickup time whey they weren't + rated, the guy at the shop shrugged, called their other shop and came back with "well, if a tank's previous hydro wasn't plus rated we wont plus rate it", and in the same breath said that they "honor plus ratings for life, that if a tank has been plused before its always plused".

The exact same shop guy was the same one who could not understand why I wanted to know capacity in cubic feet of the tanks. When asked if he knew, he said yeah about 2400. I told his that is just the working pressure and only lets me know how full my tank is, but not how big it is. He couldn't wrap his head around the concept, nor why I would care? He kept asking how deep I dive, suggesting that it would last as long as any other tank filled to 2400 PSI.

Fortunately I am not *that* stupid and I wont end up dead because of his ill advise.

So am I SOL? Can these tanks be plus rated again, should I go back and demand they do the service I asked for?

[Nwbrewer]

I don't know if you're SOL or not on the hydro, but find another shop. As expensive as dive gear is, this type of idiocy is something I don't think we all should put up with. It's almost as bad as "fill guy" who think all tanks go to 3000 because he's only ever filled al80's. :shootself:

[dsteding]

I don't know if you're SOL or not on the hydro, but find another shop. As expensive as dive gear is, this type of idiocy is something I don't think we all should put up with. It's almost as bad as "fill guy" who think all tanks go to 3000 because he's only ever filled al80's. :shootself:

My understanding is that you can put the plus rating on a tank at any time--these guys don't know what they're talking about (more so because of the comment about tank size being PSI).

[Dmitchell]

I don't know if you're SOL or not on the hydro, but find another shop. As expensive as dive gear is, this type of idiocy is something I don't think we all should put up with. It's almost as bad as "fill guy" who think all tanks go to 3000 because he's only ever filled al80's. :shootself:

My understanding is that you can put the plus rating on a tank at any time--these guys don't know what they're talking about (more so because of the comment about tank size being PSI).

The + rating can be added at any time as long as the retester has the REE # for that cylinder. In the case of the Coyle cylinder that might be hard to come by. Since these were Hydro's by UWS you should speak directly with the Hydro person.

We had a big battle with a local Mine Rescue over this. They wanted their rescue rebreather bottles + stamped but could not provide Fire King with a certified REE# so Fire King could not legally + Stamp them. We went back and forth for months.

Them telling you that they honor it even if it's not there is BS, for them to overfill a cylinder is against the law.

[trevorrowe]

The + rating can be added at any time as long as the retester has the REE # for that cylinder. In the case of the Coyle cylinder that might be hard to come by. Since these were Hydro's by UWS you should speak directly with the Hydro person.

I didn't know what REE meant in terms of scuba tanks (or at all for that matter) so I did a quick google search. Found this interesting comment somewhere:

If you are buying a used tank, especially a low pressure (LP) tank, look around the top of the tank where the serial number is for “REE” and then a number. This Rejection Elastic Expansion (REE) number is what is used to give the LP tank the “+” rating so it can be filled to 10% over the service volume stamped on the tank. Without the REE number, a hydrostatic test facility will only rate the tank to the service pressure stamped on the tank. Unfortunately, LP tanks are marketed according to their “+” volumes, so if you have a LP 95 that cannot get its rating, then you really have a LP 85.

It may be possible to get the REE number for the tank from the manufacturer if you send them the tank serial number.

I do know both tanks are low pressure steel tanks and neither have any visible REE markings on them. Is this because they are too old and they didn't used to mark REE? Would it be in my best interests to try to contact tank manufacturers or should the shop doing the hydro do that for me?

It doesn't look promising on getting these tanks plus rated anytime soon.

[CaptnJack]

It is not worth fighting to have these officially plus rated. Find a shop (or buddy with compressor) willing to fill them to 2400 and move on. Basically its a ton of work to plus rate a tank absent a REE number, e.g. Fire King won't do it. REE's don't exist for the lp72 (which was made by PST and they are defunct). The Coyne tank is an lp66 and for that sized tank its not worth it either. Sell them for ~$25-50 each on Craig's list (to someone like me who might want a boat O2 bottle, although I don't right now). Or live with the much reduced capacity at shallow sites like EUP.