Help me understand the # on a tank

[Gabriel90512]

im looking on ebay and i want to get 2 tanks (80s)

I dont understand the #'s on the tanks

DOT 3AA 2250 HJ 358981 5-71+ 1-79 4- 87 1-92 6-97

can some one teach me how to read the # ...

i dont want to just know what them mean .. but i want to be able to read them.... if im looking at another tank....

(as you can see im trying to learn)


I also wanted to know ... if im going to be diving aluminnium how much more LBS do i need to add over the lbs i use on a steel tank.... thanks

Scuba Gabe

 

[RIOceanographer]

DOT 3AA 2250 HJ 358981 5-71+ 1-79 4- 87 1-92 6-97

DOT= US Dept of Transportation... basically a gov't approval stamp. All US tanks have it.

3AA= This code means the tank is made of steel. 3AL would be Aluminum.

2250= the rated pressure of the tank 2250 PSI. Some steel tanks may also be plus rated. The plus means it is rated for a 10% overfill beyond 2250 or whatever the rated pressure is.

HJ 358981= Serial Number and manufacturer (HJ). Not sure who HJ is.

5-71+ 1-79 4- 87 1-92 6-97= the Hydrostatic test dates. May, 1971, Jan 1979, April 1987, Jan 1992 and June 1997. The 5-71+ indicates on that hydro the tank was approved for the 10% overfill I mentioned earlier. It was not approved for the 10% on later inspections.

 

[LUBOLD8431]

im looking on ebay and i want to get 2 tanks (80s)

I dont understand the #'s on the tanks

DOT 3AA 2250 HJ 358981 5-71+ 1-79 4- 87 1-92 6-97

DOT= Department of Transportation
3AA = means that the cylinder is made of steel
2250 = is the service pressure
HJ= is the manufacturer
358981 = is the serial number
5-71+ = is the original hydro with a plus, which allows a ten percent overfill
all the other dates are subsequent hydro tests

I also wanted to know ... if im going to be diving aluminnium how much more LBS do i need to add over the lbs i use on a steel tank.... thanks

Scuba Gabe

Depends on what the buoyancy is of the steel tank, among other things. If you are going from an AL 80 to a PST E7-100, it is about 5# difference.

 

[Gabriel90512]

so that tank is older then me lol

is that old for a tank ?

 

[Green_Manelishi]

DOT= Department of Transportation
3AA = means that the cylinder is made of steel
2250 = is the service pressure
HJ= is the manufacturer
358981 = is the serial number
5-71+ = is the original hydro with a plus, which allows a ten percent overfill
all the other dates are subsequent hydro tests

Depends on what the buoyancy is of the steel tank, among other things. If you are going from an AL 80 to a PST E7-100, it is about 5# difference.

The 2250 and 5-71 obviously indicate an old tank. Not that there is a problem with that but you might consider a newer tank capable of holding more gas at a higher pressure. The old "72s" were actually more like 66s. For that matter an AL80 is actually more like a 77. Nor is a .38 really a .38 ... it's a .357. But I digress.

 

[Mako Mark]

Gabriel, dont buy this tank, it is really old and you should get a much newer much better one, keep looking. You understand how to read the markings now?

 

[Green_Manelishi]

so that tank is older then me lol

is that old for a tank ?

More than one of us owns a tank of that vintage but I would not encourage you to run out and buy one. I agree with CCMark ... find something newer ... at least from the "Big 80-s". :dazzler1:

 

[skywalk234]

I agree go with a newer tank.

 

[Gabriel90512]

Im 100 % with you .........
i have a rule only dive with gear that is younger then me
lol

some one from here has 2 tanks that i might get .....

I do understand how to read the #'s now
thanks for all the help.


so A AL 90 is more like a AL 85 ?

 

[Green_Manelishi]

Im 100 % with you .........
so A AL 90 is more like a AL 85 ?

Buy STEEL. It's more expensive (probably) but worth it.