Need some cylinder advice!!!

[DA Aquamaster]

I've been using, buying, testing and VIP'ing steel 72s since 1985 and I've also never seen a 2250 psi service pressure steel 72 with the REE on the shoulder. It's true that documentation on some of them can be impossible to find, and even when you can some RINs are not fond of doing the plus rating anyway due to the extra effort and match involved.

Faber made a mid pressure 3000 psi steel 72 that is shorter, larger in diameter and heavier than a vintage steel 72 and those usually do have a REE number stamped on them. They are not nearly as nice to swim as a steel 72.

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As noted above 2400-2500 psi does not seem to be an issue with most shops. I fill my own steel 72s to the 2,800 psi on a regular basis and at that pressure they hold 80.5 cu ft. On occasion I'll go to 3,000 psi and 86 cu ft.

 

[Ulfhedinn]

Here is the best pics I could get of the two tanks. Im working on getting that black crap off them.

Tank 1
https://www.dropbox.com/s/ehla3n703lz6st3/IMAG0197.jpg

Tank 2
https://www.dropbox.com/s/o7c87yrkb5d843p/IMAG0198.jpg

 

[rjack321]

That black stuff is an exterior vinyl coating. Its terrible at trapping water and salt. And thus they can't be properly visualed until its gone. They look galivanized underneath so hopefully they are sound.

(as all the others said, vintage 72s just dont have REEs stamped on them)

 

[nwbrewer]

I had that vinyl stuff one one of mine, a heat gun and some VERY careful work with a razor knife and I took it all off in about 10 minutes. FWIW min was galvanized underneath. (At least it looks galv. and hasn't started rusting...)

 

[DA Aquamaster]

As posted on CDF, tank 1 received it's initial qualification from Authorized Testing (the stylized "A" is their stamp for the required third party initial qualification) in February 77. I'd need to see the rest of the numbers on the tank to be more definitive.

Tank two was made by Norris Industries (the HJ in the serial is a Norris indicator) and the service pressure of 2250 psi suggests it is a steel 72. If it's 6.9" in diameter (21.67" around) and about 25" tall, then it's a steel 72. Norris made great tanks and US Divers among others marketed them under their banner. They will often be stamped "USD" or "US Divers". They can be found in galvanized finish as well as vinyl coating over galvanized and may or may not be coated inside. US Divers did sell some un galvanized tanks with a vinyl coating, but I've never see a Norris made tank in this configuration.

As noted above some careful scraping lengthwise along the tank with a box cutter or single edged razor blade will remove the coating. It's it's really well attached, hitting it with a citrus based stripper will loosen it enough to scrape. Messy but do-able. In most cases the underlying finish will be near new, with the longer exposed galvanized finish looking darker.

Back in the day, the test facilities stamped these tanks with heated stamps so that the coating melted around the numbers and sealed the tank. Most RINs stopped doing that long ago and that became one of the many things (along with normal use and dings) that led to compromised coatings and the need to remove it.

 

[Paladin]

That black stuff is an exterior vinyl coating. Its terrible at trapping water and salt. And thus they can't be properly visualed until its gone. They look galivanized underneath so hopefully they are sound.

(as all the others said, vintage 72s just dont have REEs stamped on them)

I have a couple of old Healthways (Norris) 72s that are vinyl coated over galvanized steel. I have never had any problem getting them hydroed or inspected.