Another free vintage tank, what is it?

[Eric Sedletzky]

My dive shop begged me to take this old tank for free because it wasn’t something they wanted around so I took it.
I “think” it’s an old CO2 tank converted into a scuba tank.
It’s a little shorter than a 72 but appears to be about the same diameter. The markings are:
ICC-3AA1800 (?) the 1800 is not very clear but I suspect that’s what it is. Following is another number F470498 (serial number?)
Then “C-O-TWO FF CO” below that.
It has an insert sleeve to convert 1” down to 1/2” tpt
and the bottom has 6 bumps around the perimeter so the tank will stand up without a boot.
What should I do with it?
make a bell, or is it worth hydroing?

 

[James79]

Looks like a converted fire extinguisher.... C-O-TWO is/was a fire fighting equipment company :
C-O-Two Fire Equipment Company
Regarding what you should do with it... send it to me! I'll try to put it in service for my 10 y.o. (he currently has one 1943 1800 psi 38). If you insist on making it a bell or some such, I would take the valve off your hands.
Respectfully,
James

 

[Eric Sedletzky]

It’s yours free.
If you can cover shipping that would be swell.

 

[runsongas]

apparently the length makes them comparable to AL50s (and not prone to alloy issues as they are steel), so some vintage divers use them with a double hose.

 

[James79]

apparently the length makes them comparable to AL50s (and not prone to alloy issues as they are steel), so some vintage divers use them with a double hose.

I, and my 10 y.o., are working on being "some vintage divers!"

 

[Eric Sedletzky]

Why would they do a hydro on 2-47
Then another on 11-48?

 

[James79]

If I had to guess, the place that bought it just did all there tanks at one time. Putting them all on the same schedule. Just a guess though.

 

[tridacna]

When were the 5 year Hydro rules established?

 

[John C. Ratliff]

When you get it into the water, check the buoyancy. The steel 72s were well balanced for both freshwater and salt water, but for CO2 tanks, that was not a consideration. This one may float a bit, and need some weights.

SeaRat

 

[Luis H]

Why would they do a hydro on 2-47
Then another on 11-48?

There are several reasons: they might have been concerned about damaged due to fire or other incident, like said it might have been a convenient time, etc.

When were the 5 year Hydro rules established?

The 5 year cycle has been around for a long time. Long before this cylinder was made.



I have owned two cylinders with the 5 bump on the bottom.

I actually own one right now that was given to me. It is hot-dipped galvanized and it has the standard modern 3/4" NPS threads. So it was obviously manufactured for diving purpose.

In the 70's I also had one with the 1/2" NPT tapered threads that was sold as a scuba cylinder by Seamless (the US distributor of Nemrod). That one had a Nemrod/ Seamless valve and it was painted. It might have been galvanized under the paint, but I can't remember. I just hated the 1/2" neck opening when it cam to VIP. I worked at the the dive shop so I did the VIP's.

Both of this cylinders are stamped 2250 (psi) and other than the bottom they seem to behave like any other steel 72.

This one does seem to be a converted CO2 fire extinguisher based on the pressure and the stamped markings.