US Divers Triple Tanks

[ovalis]

I've seen both tanks you are talking about and yes they were both US Divers tanks manufactured by Pressed Steel. I don't know the answer as to why they decreased the psi rating from 2600 to 2250, but I'm going to guess that might have something to due with the weight/buoyancy issue. Only in 1954 USD also made 2 other tanks besides this little 44 and the standard 72. The made a 80 cu ft tank rated at 2600 psi & a 90 cu ft tank rated at 3015 psi. I have a few of the 2600 psi tanks that I used to dive a lot, and it would sink you like an anchor. You could drop 8-10 lbs off your belt compared to diving a steel 72. I know the buoyancy/physical characteristics of the 44 are different compared to the 72, but I think the 2600 psi versions might have been pretty heavy. They changed over to 2250 psi in 1956 for the 72, and I assume the 44's were changed at the same time as well.

 

[dead dog]

The first triples sold by SPACO and Rene Bussoz were made from surplus life raft bottles and an had a working pressure of 2100 psi. I have multiple tanks from this period with an original hydro of 1949. These have true hemispherical bottoms. I have almost identical tanks also with hemispherical bottoms from 1953 and these are rated to 2165psi. The one you have from 1954 is also likely surplus and this would likely explain the seemingly random rating 2600psi. At this time it was catch as catch can with cylinders. They are all over the place. As you get to the semi hemispherical tanks of the late 1950's they we purpose built and all carried a 2250psi rating. Your best bet is to look for a 2250 tank to complete your set. Do you have photos of the triple set in question?

-Ryan

Here are some closeups o the samp mark.



Bill
dead dog