Questions about Steel 72's

[Yerba Mate]

I recently had a steel 72 borrowed to me on a long term basis.

It looks like, if I want to use it, I will need to get a visual and get a hydro test in the near future (i.e. might as well do it all at once).

Anyways, I'm trying to figure out if it will be practical to use for general diving with other's using AL80's. I use my air slightly to somewhat quicker than others I find, so if I'm gonna be taking a hit in terms of capacity, this tank might not do it for me.

Here is the original stamp for the tank (going around the tank):
DOT-3AA 3000-88/9082/ 084 M8303 FABER ITALY 10 "SYMBOL" 88 + SCUBAPRO
(Where symbol represents a wierd looking symbol for Faber I believe).

The original hydro was for 95, and a second hydro was for 2000. I do know what a lot of the stamp means, but I'd like it if someone could interpret it more fully.
The tank is also 21 inches high and 6.5 inches across (approx).

I'm assuming that this tank holds 72 cu.ft. at 3000psi, which might not be enough to keep up with other's who have good air consumption and have 78 cu.ft. However, is this tank certified for the plus rating? or Can it be recertified for the plus rating? My dive shop said that the plus rating is only good for the first hydro, but I've heard other's say it can be recertified to the plus rating. And if I got it recertified to the Plus (assuming that this tank is a plus tank), would shops recognize a tank with the plus rating that's on it's third hydro?

So, thanks for all your help.
Dave

 

[Drew Sailbum]

DOT-3AA = Cylinder manufactured of a Chrome Molybdennum Steel meeting the spcifications laid down by the US Dept. of Transportation for the 3AA designation
3000 = working pressure of 3000psi
88/9082/ 084 = serial number, most likely
M8303 = manufactured by FABER
FABER ITALY = kinda redundant, eh? manufactured by FABER Italy
10 "SYMBOL" 88 = Original hydrostatic test in October 1988. The symbol is the mark of the original hydro tester.
+ = Rated for 10% overfill
SCUBAPRO = distributed by Scubapro

Yes, cylinders can have the "plus" rating renewed. It requires a few more steps on the part of the hydro tester and not all testing stations are set up to do this.

A cylinder which was not renewed as a "plus" rated cylinder at one hydro can regain the "plus" rating at a subsequent test.

 

[DA Aquamaster]

All that is needed for a hydro tester to do the addiitonal steps and the calculation required for a plus rating is documentation from the manufacturer regarding the REE number. On newer Faber tanks this is stamped on the tanks (REE 45, etc). For older tanks you can get it from the manufacturer.

The Faber 72 is about 6 lbs negative when empty and nearly 11 pounds negative when full so you can take a substantial amount of weight off your belt compared to an AL 80.

The Faber 72 will hold 71.4 cu ft at 3300 psi and 65 cu ft at 3000 psi which is nearly identical to the capacity of a normal 71.2 at 2475 psi and 2250 psi.

In comparison an AL 80 holds about 77 cu ft at 3000 psi. So you are potentially going to be 6 to 12 cu ft shorter on air than your AL 80 buddies assuming they get a good 3000 psi fill. This equates to a difference of 225 to 550 psi in the average 80 cu ft tank.

However, if your buddies only get a 2800 psi fill in their AL 80's (pretty common with hot fills) then they are only going to be starting with about 72 cu ft anyway. So if you can get a plus rating and are careful to ensure the tank gets an honest 3300 psi fill, the air capacity in practice will be pretty much identical to the average 80 cu ft rental tank.

I dive plus rated steel 72's exclusively and I also fill my own tanks. So in practice I find I normally have the same amount of air as the majority of the AL 80 equipped divers I encounter.