Another steel tank question (Genesis)

[fl-diver]

I just got 4 hp100 genesis with a "package" of used dive gear. I have read a lot about the weird angled valve and 7/8 threads and I don't mind converting my reg to din. 2 tanks are 95 original hydro and 2 are 89 original hydro. Current hydros in 2005 and have current VIP. The exterior looks good on all. I feel fine about the 95's but are the 89's any good after the 2005 hydro expires?
How long should I expect these to last?

 

[Jimmer]

I would expect a long time. My instructor has been using those for like 15 year or something and they are still going strong. I believe they were built by PST and should be every bit as good as PST's other older tanks.

 

[Luis H]

My oldest steel tanks are from 1957, my newest (not including my wife’s two new 80 cu ft tanks) are from the mid 70’s. Several of my tanks were made by PST. I would be pretty unhappy with a galvanized steel tank that didn’t last at least 50 years…unless I allowed it to rust inside.

 

[v--Locke--v]

more over, what do i need to upgrade my "angled" DIN to a newer straight DIN or an H Valve DIN?

(I have the same tanks...)

 

[Jimmer]

more over, what do i need to upgrade my "angled" DIN to a newer straight DIN or an H Valve DIN?

(I have the same tanks...)

You need to hunt down a Thermo valve with the 7/8" UNF neck thread. I have no idea how difficult that will be.

 

[mfalco]

My oldest steel tanks are from 1957, my newest (not including my wife’s two new 80 cu ft tanks) are from the mid 70’s. Several of my tanks were made by PST. I would be pretty unhappy with a galvanized steel tank that didn’t last at least 50 years…unless I allowed it to rust inside.

I had a galvanized steel PST LP95 that was 5 years old when it failed hydro. A year before hand I had a steel tank from the 60's that still had a j valve pass hydro.

 

[dannobee]

Not all of the Genesis tanks were PST's though. Some were Asahi's. If it says "SPUN" on the neck, it's an Asahi.

The Asahi's are more rust prone, but the PST's fail hydro more frequently. Take your pick. :11:

The 7/8" valves are getting more rare though.

 

[Luis H]

I had a galvanized steel PST LP95 that was 5 years old when it failed hydro. A year before hand I had a steel tank from the 60's that still had a j valve pass hydro.

I would be very un-happy with that, but my first reaction is that the hydro facility probably did not follow proper round-out procedures. I know some feel that it shouldn’t have been necessary, to need such procedure, but I personally don’t find it unreasonable. It is just part of the nature for very thin wall pressure vessels…they need to be perfectly round to be predictable.

The conventional chrome-molly (3AA) steel tank has shown an excellent track record for durability. Most of them are made of ASTM 4130 which is a very well known and predictable alloy. I am not familiar with the steel alloys used in the newer special permits (SP) tanks, but logic tells me that they are pushing somewhat the envelope in the design and therefore some properties may be somewhat compromised.

 

[fl-diver]

I am not real concerned about the angle but if you are looking for valves look here.
Buy XS Scuba Modular Din Valve VA378L with reviews at scuba.com

 

[pescador775]

The LP95 is not "thin wall".

The older "Genesis" branded HP tanks appear to hold up over the years in contrast to later production HP cylinders from the mfgr, PST. I doubt that "rounding out" was done with any of the older HP tanks and they still passed hydrostatic test. Almost nobody had heard of this procedure until about Y2000. It seems that the quality of PST tanks, especially the HP type, varied from time to time and that the quality of individual tanks including those which are well maintained, is not predictable. It may be coincident with steel "dumping" by foreign suppliers or possibly just the reverse. We will never know.

I don't know why you would change out the valves unless doubling up. The cave divers (DIR) don't like the angled valves but they are often grousing about one thing or another.