Help identifying old pst tank

[divinginn]

I was just at my lds and he was showing me some tanks he just bought off someone,he asked me if I knew what they were.I was guessing some 119s but were not sure if they made them that far back. They were 3500 psi hp pressure tanks with the din fitting with the small neck,smaller than standard valve bore,they were app. 24 inch's and looked like 8 inch diameter,sitting next to a steel 72 they looked quite a bit larger. Any one have a idea what these are the original hydro was in 91.

 

[divinginn]

Anyone?

 

[Gilldiver]

I'll take a shot that they are Sherwood Genisis 100's. I have a set in the garage.

The valves were angles up about 20 degrees from horizontal and have a 1/2" streight thread that is O-ring sealed.

They came out in the late 80's early 90's. At the time the choice for almost any set of doubles were steel 72's or aluminum 80's. So when the 100's came out they were real popular with the wreck divers.

 

[divinginn]

Yes I think the valves were angled up,I was thinking of doing some horse trading with him for the tanks. Thanks

 

[SparticleBrane]

They will probably last awhile but will be a real PITA when it's time for VIP and possibly a tumble, with the thinner neck than the current standard.

 

[divinginn]

They need hydros,never been rehydoed,they did have air in them. They may have been 7 and a quarter inch tanks,but they looked pretty fat compared to the steel 72 next to it.

 

[divinginn]

How hard are manifolds to come up with on these small necked tanks,but I would probably go side mount if I go on to cave training.

 

[Gilldiver]

The manifolds come up every now and then on Ebay. You just have to keep looking. Some may have problems with the design as it uses face seal O-rings vs. the barrel seal that Thermo and the other current manufacturers use. I have never had a problem with the manifold and only break it apart at hydro time for a full rebuild.

As for how lonng will they last? I don't know, but my double 100's are just about 20 years old now and going strong. Next hydro is in 3 years, I'll let you know.

 

[Jimmer]

I found a manifold for my instructor Sherwood (PST) hp 100's, it was a Dive Rite with the 7/8"s neck, and was identical to current barrel style manifolds. Keep an eye out for one of those, and you'll be set.