eddy current testing is accurate only for the old alloy (I don't recall the number), but it was walter kidde tanks and luxfer prior to 1989. eddy current testing on current alloys (post 1988/89) often return false positive and is not recommended.Originally Posted by ktomlinson
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"Learning the techniques of others does not interfere with the discovery of techniques of one's own." B.F. Skinner, 1970.
6351
"Those who make peaceful revolution impossible will make violent revolution inevitable." --JFK
Not according the Luxfer, check out the section on 6061 alloy tanks (post 88) in the document I've linked to below. Eddy current machines are used to check a lot more than just the 6351 alloy. My machine is off being calibrated now. Many folks skimp on sending it in for calibration, but doing so will help eliminate false positives. It is interesting though to note our various understandings of the process.
Earlier it was mentioned that VIPs were not the law, I can't find it now, but there is a DOT regulation that does require a visual inspection of the cylinder every time it's hydro'd. It does not specify the specifications to which the cylinder should be inspected, though.
http://www.luxfercylinders.com/index...ponent&print=1
I won't look in the CFR, but you are correct, a visual is a required part of the Hydro and as far as I know is the only legally required visual inspection. Of course I'm not saying for example that if you knock a tank over, you shouldn't look to see if you have bent the valve handle or something, required to do so or not.
This is my opinion, some re-build their own regs. I believe if your competent enough to do that, then you can do your own VIP as well. Honestly if I thought there might be a problem with my tanks, there aren't many people I'd trust to do a VIP for me. I've watched many a "tank monkey" I think they are called drain tanks, knock the valves out with a rubber mallet, sort of take a look with a flashlight and re-install the valve with the old O-ring with a little Dow Corning silicone grease of course and smack the valve with the rubber mallet and re-fill the tank. More often than not, this is a VIP. Valves have a torque value, but I've never seen a torque wrench used and if I do, I'm sure it isn't calibrated.
Jax, I'm willing to bet your more competent than most who do VIP's, however if you chose to have someone else do it for the convenience of it, your call.
You should switch to an O2 compatible grease, especially for deco tanks.
Life moves pretty fast. If you don't stop and look around once in a while, you could miss it.
-Ferris Bueller
The most certain way to stumble into the future, is to live your life looking over your shoulder.
-Jeff Hawes after getting a huge mulligan...
Huh?
I don't use silicone for anything except flashlight O-rings etc. But I have had silicone put on my O2 clean tanks making them of course no longer 02 clean. My comment was about some shops I have seen that regardless of your request will use silicone. I try to keep all tanks 02 clean.
And how many are still paying for a VIP along with your hydro?
"Those who make peaceful revolution impossible will make violent revolution inevitable." --JFK
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