Dacor Steel Tank

[lonestardiver]

I was given an old Dacor Steel tank that I would like to use for diving...

I would like to see if someone could help me identify the Markings on the tanks...

ICC34422250
20041
Dacor
7L65+PST

I figured the first line was the service pressure and the last line is the first Hydro stamp. Im not sure what "20041" is....

Also this tank does not have a valve and appears my 3/4 size valve is too big... Do they make valves for these tanks or do I need to find an older valve to use?

I was told this was a 72.. is this correct?

Sorry all the Newbie questions.. .I havent used a tank this old before but I hope I can!!!

THanks...

 

[Luis H]

The first line actually reads:

ICC 3AA 2250

ICC = Interstate Commerce Commission
This was the government agency that regulated tanks and was replaced by the DOT (Department Of Transportation). This is normal on tanks of that era.

3AA is the code that specifies chrome molybdenum steel seamless pressure cylinder. This is the same code used today for most LP steel cylinders. In other words, this tank is made out of the exact same material and under the exact same specifications as many new tanks sold today (mostly the ones rated to 2400 psi).

2250 is the rated working pressure in psi.

The 20041 is the serial number

7L65+PST
The last line says that the first hydro (and close to the manufacturing date) is 7 / 65, in other word July of 1965.

The + means that it was originally rated for 10% overfilled and if the hydro tester adds the + on the next hydro it can again be filled to 2475 psi (10% over 2250 psi)

PST is the manufacturer = Pressed Steel Tanks.

If the tank has a narrow ½”NPT neck you will need a vintage ½” NPT tapered thread valve. They are commonly available on eBay.

The tank is probably a steel 72, but you need to post pictures or even better take some dimensions. The diameter should be about 6.9” and the length I think is about 24” (I am not sure about this last number).

Note: to add the +, you will need the REE number which is 58.4 for a PST steel 72 tanks. The document confirming this number is around.

Be aware that some ignorant (or worse) dive shop owners/employees will refuse to deal with old steel tanks. The ½” NPT valves is also a particular issue that very ignorant LDS will not service or even fill tanks with that valve. In Texas you are hopefully OK, but don’t bother taking it to Florida. Up here in Maine we are lucky that we have good knowledgeable LDS.

Good Luck

 

[lonestardiver]

Thanks Louis.. My eyes are getting bad.. You are correct on the ICC 3AA 2250.

Pictures of my tank to follow...

 

[lonestardiver]

 

[lonestardiver]

 

[lonestardiver]

 

[lonestardiver]

 

[DA Aquamaster]

A few comments:

1. The tank appears to be vinyl coated, with a galavanized finish underneath. If the coating is loose at all you will need to strip it off - at least the loose bits and preferrably all of it if it is starting to peel - as water can get trapped under it, cause rust and prevent proper inspection of the tank.

The galvanized finish underneath is good news - USD made them in ungalavanized finishes as well and they end up being a lot more maintenence once the vinyl is removed - and more prone to damage under the original vinyl.

2. The odds are also good that it has a coating inside as well. This is one of those good sounding ideas that was not so hot in the long term. It prevents rust intially but over time the protective coating would develop pin holes that would then trap moisture under the coating, cause rust and hide it from a visual inspection. If it is present, you'll have to tumble it to remove it and that will require about a week of tumbling to get it all out. Some shops won't bother.

3. The boot on the bottom is for all intents and purposes non-draining. it is not uncommon to remove it and discover lots of rust and pitting. They vinyl coating, if intact may have prevented that, but lose the boot and use a newer self draining boot.

4. From the look of the neck and threads in the picture, the tank is not pristine inside and will at a minimum need to be tumbled even if not coated inside.

-----

From the height it does appear to be a steel 72. I am assuming it is 6.9" in diameter and that the 5" apparent diameter in one of the pictures is due to the perspective of a camera placed fairly close to the neck and tape. a Similar perspective issue appears in the other picture where the standing tank has been fore shortened to some extent.

 

[lonestardiver]

Thank you for your detailed observation...

I have a couple of questions I would like to ask in regards to your comments...

1. The tank appears to be vinyl coated, with a galavanized finish underneath. If the coating is loose at all you will need to strip it off - at least the loose bits and preferrably all of it if it is starting to peel - as water can get trapped under it, cause rust and prevent proper inspection of the tank.

Since this is vinyl coated... Is it a matter of just stripping it off by hand or can some type of solvent assist in removal?


4. From the look of the neck and threads in the picture, the tank is not pristine inside and will at a minimum need to be tumbled even if not coated inside.

When tumbling is done does that include them removing rust on and around the threads inside the neck?

 

[oldmossback]

Howdy Lonestar......

I know this is a long drive, but if you can not find a good 1/2" valve locally in North Dallas, Fort Worth Scuba Schools in west Ft Worth might still have one or two........Don Reese owns the shop........and he is vintage.......established his business back in 67 or 66.......anyway, he is crusty but has a wealth of knowledge.....he can tumble and hydro that tank too........he rebuilt one of my USD twin manifolds a few years ago........he knows his stuff.........

But it is a long drive from Plano......his shop is on the benbrook traffic circle........

Oldmossback