Posted by kenkurtis on October 26, 2000 at 01:24:35:
In Reply to: Re: In Defense posted by tleemay on October 25, 2000 at 17:24:33:
This is pure speculation on my part but if the valves were that loose, I don't see how any air could possibly been put in the tank. (Perhaps they never got filled in the first place. Did this guy gauge the tanks when he picked them up?)
You're dealing with three things to form the seal: (1) the tank, (2) the valve, and (3) the o-ring that goes between the two. If you're missing any one of these from the equation, the tank won't hold air.
When you screw a tank valve in, it takes about 10 turns for it to come flush with the tank. The o-ring pinned between the valve and the tank makes the seal. (A metal-to-metal seal here will not hold air.) At this point, you can either just hand-tighten the valve (perhaps an additional quarter turn) or tap it with a mallet for a snugger seat (maybe half an additional turn).
Once you put air in a tank that's had the valve seated, there's no way you could get the valve off just by turning it. (It's as hard as taking your reg off your tank valve with a full tank of air and without turning off the air and purging the reg.)
Something just doesn't add up in this story. If the valves weren't screwed in, it should have been noticeable (the valve would have stuck up about an inch or so above the tank). And if they were screwed in, most leaks (but not all) should have been audible.
It still sounds like shoddy service, but there's just something about this scenario that doesn't seem right.
Ken Kurtis
NAUI Instr. #5936
Co-owner, Reef Seekers Dive Co.
Beverly Hills, Ca.