Question are they 3/4" or 7/8" valves

[rattlenbones]

I just got a free SET of steel tanks and want to know what they have for valves 3/4"
or 7/8" with out taking the valves out because i don't have time to work with them right now, MAYBE IN A FEW WEEKS....
they were last hyd. in 01 and the last vis. is 05, they have air in them so i have hope for no rust inside, out side is good,
i wan't to double them and give my double 80's to my son.
THE #'s - OMS 121 DOT 3AA-2400-93/9010 077 M8303 06/93

Thanks Bones. Oh yea WOO HOOOOO ( i hope there good, i hope there good )

[saxplayer1004]

3/4.
The PST HP ones are the small ones. You can check since the bottle neck will be the same size as your AL80's for the 3/4" threat, and the 7/8 will be much narrower. Beware doubling the 121's, they're heavy suckers. Fairly light in the water but well over 50lbs each dry

[rattlenbones]

Thanks
I'll watch my back :shocked2:

[Scared Silly]

FYI, the only cylinders that used 7/8" 14UNF valves are those rated at 3500psi. The other modern cylinders are 3/4". Older steels (circa 50s&60s) could be 1/2"