US Divers Triple Tanks

[dead dog]

The C with the L inside is the symbol for COCHRAN LABS. They were the hydro test lab typically used by Pressed Steel Tanks (PST).
PST was the primary supplier of steel cylinders for US Divers.

I understand about the markings stamped on the tanks.
What I don't understand is the two different pressures 2600 psi and 2250 psi

 

[james croft]

I am also searching for one of those tanks. I have two of the PST tanks rated for 2250 but need one more to finish up a set of triples. All of the triple sets I have seen have been 2250. If memory serves me the two tanks I have were born in 1958. I have not seen any with that higher pressure rating before. How does it compare with the lower pressure tanks dimension wise?

 

[dead dog]

I am also searching for one of those tanks. I have two of the PST tanks rated for 2250 but need one more to finish up a set of triples. All of the triple sets I have seen have been 2250. If memory serves me the two tanks I have were born in 1958. I have not seen any with that higher pressure rating before. How does it compare with the lower pressure tanks dimension wise?

They are the same size in height and width. same 1/2" thread neck. I checked all the manuals with no help.

 

[al248005]

Are you talking about these...they just popped up on my local craigslist Scuba tanks

 

[agilis]

Are you talking about these...they just popped up on my local craigslist Scuba tanks

I think not. the tanks under discussion are 40 CF triples, and the issue is why seemingly identical tanks are differently rated, some at 2250 psi and some at 2600. I've never seen a scuba tank from that era rated higher than 2250.

 

[rndboulder]

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

 

[Akimbo]

Surplus cylinders in those days could explain a lot. The US was swimming in huge war surplus outlets.

But how did US Divers get all that stamped on the necks?

ICC3AA 2600
US DIVERS CORP.
1045 BROXTON AVE.
L.A. 24 CALIF.
10651
RENE 5-54 ( WITH A L INSIDE THE C ) PST

I HAVE SEEN MANY 2250 PSI TRIPLE TANKS BUT NEVER A 2600 PSI TANK…

Buying a pallet of surplus cylinders and stamping all that data on the necks seems pretty brazen, but maybe ICC wasn’t so up-tight in those days. I wonder if cylinder manufacturers were caught with a lot of excess inventory or had war production contracts cancelled that US Divers scooped up?

This is turning out to be a dive history archeology exercise.

 

[danvolker]

When I had the triple wight he plastic fairing that Akimbo showed the picture of....I am pretty sure that was around a 3000 psi series of tanks..or maybe even much higher.....
I remember next to NO shops back then could fill to this pressure, and most were shocked that the system indicated it could take such a high fill pressure.

But again, my memory back this far is sketchy.....it was not all that important to me at the time.

 

[Tom Winters]

The tanks of the future way back when were the AGA Divator system. It was a triple-manifolded rig that was designed for 5000 psi service. No fairing or any of that Cousteauish nonsense - just lots of gas in three skinny cylinders. Even the US Navy didn't mess with this stuff. I never ran across anyone who actually had one, and pumped to available service pressures then made it good for cleaning hulls and not much else. For the cost of two of those rigs, you could buy a 34' Hatteras with gas engines.

 

[Akimbo]

When I had the triple wight he plastic fairing that Akimbo showed the picture of....I am pretty sure that was around a 3000 psi series of tanks..or maybe even much higher.....
I remember next to NO shops back then could fill to this pressure, and most were shocked that the system indicated it could take such a high fill pressure...

I’m pretty sure they were small Aluminum cylinders that were 3000 PSI just like the 80 Ft³. I think Rich Keller here on Scubaboard still has a set without the cowling.

The tanks of the future way back when were the AGA Divator system. It was a triple-manifolded rig that was designed for 5000 psi service. No fairing or any of that Cousteauish nonsense - just lots of gas in three skinny cylinders...

I never saw the triples but still use the doubles, the AGA Divator 324 sold by Interspiro now. The “324” stands for 300 bar/4,351 PSI, 2 cylinders, and 4 Liters (3.8 really). Heavy but really nice in cold water.
Interspiro - DivingProductPage

Here are some images, they were originally yellow.