Odd Little Tank, History?

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

lowviz

Solo Diver
Rest in Peace
Messages
7,660
Reaction score
4,717
Location
Northern Delaware ---or the NJ Turnpike
# of dives
200 - 499
I'd like to know as much as possible about this little tank. See pic, the one in the middle.

Exact same diameter as a standard steel 72.

Hydro Stampings:
The first one is: 5z 79 (huh???)
All the way down to a known test facility dating it: 7 13

Manufacturer's Stampings:
DOT 3AA2250
A2150
DACOR
8 (C with an 'L' inside of it) 70+PST

See pic, ignore my little girl who is helping me remove labels. :)

Tanks.jpg
 
That looks like it was manufactured by T. H. Cochrane Laboratory in August of 1970. The Dacor stamp is there as they had their branding incorporated during production.
The + after the 70 means that it was originally allowed a 10% overfill or (2250+225=2475 psi) if when it gets tested and passes it would either be allowed the overfill or not. if the hydro indicated the + it would still be allowed if not it would only be permitted to fill to 2250 psi. as it is a steel tank if the hydro was current you could still use it today.
I am not positive regarding the size but I think it is a 50 cft.
 
It was manufactured by Pressed Steel Tank Co. Cochran labs is the independent inspector that did the initial hydro for PST.
Also:
DOT - Dept of Transportation (Gov Regulating Agency)
3AA- Seamless Steel Tank made of Crome molybdenum steel
A2150- serial number
Dacor -reseller
8 CL 70- innital manufacturers hydro done in Ag 1970
+ - Authorization for 10% excess fill
PST - Pressed Steel Tank (manufacturer)
Other marks will be hydro marks. Prior to mid 1980, Hydrotesters could use symbols/letters for identification.
 
...//... Prior to mid 1980, Hydrotesters could use symbols/letters for identification.
Thank you, that explains the first hydro stamp.
...//... as it is a steel tank if the hydro was current you could still use it today. ...
It is and I do.
... I am not positive regarding the size but I think it is a 50 cft.
I would agree. The tanks are the same diameter and same reference pressure so the necks and bottoms can be assumed to be the same (they aren't, but they are very close) and one can then make a guesstimate by taking a ratio of the cylinder lengths from neck break to bottom break. I get 13 3/4" and 19 1/4" so that ratio times 72 cuft comes out really close to 50 cuft.

Thanks, both!
 
It is 50cf
"Back in the day", they were commonly doubled up with a single outlet manifold. I've got two of them which were made in 1980 I think. I use them for filling my inflatable boat, driving my booster, tire inflation and stuff.
 
https://www.shearwater.com/products/perdix-ai/

Back
Top Bottom