2nd hand steel 72 questions

[whaylonsmithers]

Hi All,

I just bought some old steel 72s on ebay for $10 a piece and now I want to know if they're any good. No hydro, no vis, no valves. I still haven't seen them either.

Question1. Will my new-ish Thermo valves fit alright? I anticipate the valves have a High Pressure burst disk and that the tanks will be MP. I also seem to recall a valve issue where a nearly perfect thread pattern on some old cylinders takes newer valves, but then throws up an exploding sort of an issue if it was the wrong thread type. Hopefully my memory is totally wrong on that.

Question2. Apart from crazy rust or massive dents, is there anything that should tell me to throw them in the bin rather than waste money on hydro?

Regards and thanks for any replies.

 

[Danseur]

Are these 2250 psi and 6.9" dia?

What is stamped on the shoulder in these?

You may be thinking of 3/4" and M25 valve issues....

 

[whaylonsmithers]

Apparently they are low pressure, so 2250psi seems right. Diameter is unknown. I was thinking of the 3/4" versus M25 issues now you remind me. Is it a relevant concern?

Cheers for any information.

 

[Mitchell Teeters]

I'm not an expert, but I do have two 72's. They are tough cookies. If they are not pitted you should be ok. My first one has a liner that I'm going to see about getting tumbled out. I'm scheming on one that I found behind a fill house laying in the dirt. It still had 2100 psi, and had been sitting since at least 2003, IN THE DIRT!!. Valves are available for them if you look. I like them for their buoyancy characteristics and durability. I'm going to let my boy use them as his SAC will be pretty low. And for $10, at least you have some cheap gongs for shooting, and air tanks for filling tires and what not.

 

[halocline]

Sorry, I thought I had posted on this but I must have forgotten to actually press 'post.' Your concern about the valves is not warranted; the valve issue you're talking about was with some particular HP tanks, at least that's my memory of it. Your LP72s will have either regular 3/4" threads or 1/2" tapered, and you can get new valves for the tapered threads.

When you get the tanks, look inside with a light that fits inside the tank. A string of LED Christmas lights works well (unless they blink...) and look for pits and deep-looking rust spots. If there are none of those, but some areas of surface rust, you can get the tanks tumbled, and there's a bottle brush that seems to work really well on the inside bottom of the tank. You might search for posts by Luis H, he's the one that posted about the brush.

Some LP72s had internal plastic coatings. If you have one of those and it looks pristine, try getting it hydrotested; maybe it'll be fine. Lots of hydro testers won't even test those tanks unless the coating is completely removed. I have heard of doing that, but I wouldn't want to myself. If it's coated and the coating is bubbled or cracked in any spot, you'll have to remove it or toss the tanks.

The outside of LP72s is usually galvanized under paint. If so you can remove the old paint and then coat over the galvanizing with ZRC galvilite. That product is great.

 

[herman]

While fairly uncommon, in addition to the 3/4 straight 0ringed and 1/2 tapered threads there is a 1/2 straight oringed thread....recently aquired one of these. In any case, all 3 thread types are fine as long as you have the valves.

 

[captain]

Just had a 72 with the internal coating and a spot or two of it missing and it was passed by the hydro shop as it should be if they know what they are doing.

 

[WB2GLP]

If its a DOT or ICC stamped steel tank, you may have a good buy. Some foreign tanks w/o DOT stamps are out there. No hydro shop will test them.

Lined tanks without obvious cracking should not be a problem to have tested. Trying to remove a cracked lining is a big waste of time.

The valve thread issue you were referring to had to do with installing a metric thread valve into a standard 3/4 tank thread.

 

[whaylonsmithers]

Thanks guys. All good info. I only bought them so quick becuase so many knowledgable people on this forum seem to love them and it appears confirmed. Next week I may actually seem them in the flesh but at $10/unit I'll take that chance. This may yet turn out a victory for drunken ebay-ing.

 

[Culcuhain]

I would have snatched them up. Taken them to the hydro shop and told them to tumble if needed then bought new valves and had the visual done and dive them. I have 4 lp72 and love them.