Older steel tanks

[Scoobers]

I just picked up some older (1992) HP steel tanks off of craigslist for $100. I want to double these up but I am having a hard time finding 1/2in valves. If anyone has any suggestions on where to get some half inch valves let me know.

 

[Fishpie]

Nice one. Especially if you scored 120's.
I don't think anybody makes manifolds for them anymore.
Your best bet is putting a "wanted" ad here or trolling on eBay.
Those HP "Genesis" 3500's were popular tanks to double up in the early/mid 90's when there wasn't much of a choice in large volume tanks....there should be a good number of manifolds around.
btw..make sure that the Hydro facility knows to do the pre test stretch on them and watch for flash rust.

 

[Scoobers]

They are 100s and I dropped them off at the LDS for hydro and they were familiar with these older steel tanks. Now I just need to find manifolds.

 

[scubapeter]

If you have pst sherwood genesis tanks, also marketed by us divers, they do not take the really old 1/2 inch valves, they take the newer 7/8 inch valves, but not the standard 3/4 inch that we use today. If you call john at www.northeastscubasupply.com he has brand new, old stock oms manifolds that will serve you well. I was at his shop a few weeks ago and he had them in stock.

 

[Jim Baldwin]

They are 100s and I dropped them off at the LDS for hydro and they were familiar with these older steel tanks. Now I just need to find manifolds.

I've got four HP PST tanks and they don't take the 1/2 valves. Again, check out northeast scuba supply. I looked at their website a couple of days ago and they have the manifolds that you need to complete your project.

 

[Scared Silly]

Not my auctions, but here are the left and right, just need to buy a std center bar isolator.

THERMO 300 BAR DIN OUTLET MODULAR VALVE V7030 LEFT - eBay

New Thermo V-7020 300 Bar Din Valve Right Side - eBay

 

[Scoobers]

Thanks for the replies guys but I am positive these are not pst tanks. They said us diver/aqualung all over them. Also when I dropped the tanks off at the shop we pulled the valves to see if they needed to be tumbled after they come back from the hydro and they are definitely 1/2 valves. They currently have nice 300 bar din valves but they are a strange design and cant be used for doubles. So I am still on the lookout for 1/2" manifolds.

 

[rjack321]

Thanks for the replies guys but I am positive these are not pst tanks. They said us diver/aqualung all over them. Also when I dropped the tanks off at the shop we pulled the valves to see if they needed to be tumbled after they come back from the hydro and they are definitely 1/2 valves. They currently have nice 300 bar din valves but they are a strange design and cant be used for doubles. So I am still on the lookout for 1/2" manifolds.

HP from 1992 they are PST. US divers/aqualung was the distributor. I don't beleive they ever distributed Asahi tanks although they might have. In either case if they are 3500psi service and made in 1992...

They are not 1/2" (NPT or NGT) valves although they might measure that way with a ruler. "Hp" tanks with a 3500psi service pressure were never made with 1/2" valves nor were 1/2" valves ever made in DIN - they are always yoke and seal with teflon tape not an O-ring.

You have 3500psi exemption series HP tanks made by PST (or possibly Asahi) with 7/8" valve threading. 7/8" is visibly smaller than the current 3/4" thread standard, go figure. You can get 7/8" valves and manifolds from NESS or TDL.

 

[Scoobers]

After reading these posts I decided to head back to the dive shop and look at the tanks again. The guy who originally took the valves off measured them with a tape measure and they come out to 1/2". He was just some goon running the showroom so tonight I talked to the owner who informed me that they were indeed 7/8". Now being that I have an engineering degree the logic behind why they call them 7/8" makes no sense and just adds to the confusion. Anyway I want to thank you guys for your help in convincing me to go back and question the answer the first guy gave me.

 

[Jimmer]

Being that I am an engi-ma-neer myself, I'll try to clarify things . Those tanks use a true 7/8" UNF thread. Absolutely standard threadform, nothing unusual there. If you were to measure them accurately with a vernier you would see they are 7/8" for the major diameter. Now the real weird one is the standard valve, which is referred to as a 3/4" but is MUCH larger than the 7/8" thread you have there. That is actually a 3/4" NPSM (national pipe straight mechanical) thread, which is of course a pipe thread, and the 3/4" refers to the inside diameter of the pipe that would utilize that thread. Hence why the OD of the thread is WAY larger than 3/4".

Hope that clears that up,
P.S. I LOVE those tanks. If I ever got my hands on a set of those 100's for that price, I would be dancing for weeks.

Cheers,
Jim

After reading these posts I decided to head back to the dive shop and look at the tanks again. The guy who originally took the valves off measured them with a tape measure and they come out to 1/2". He was just some goon running the showroom so tonight I talked to the owner who informed me that they were indeed 7/8". Now being that I have an engineering degree the logic behind why they call them 7/8" makes no sense and just adds to the confusion. Anyway I want to thank you guys for your help in convincing me to go back and question the answer the first guy gave me.