Pulled 2 "OLD" Luxfers from my storage...

[happy-diver]

On an angle with the threads down brush out the muck with acetone, some cloths leave fibres on some threads

 

[Bowers]

Ya VE is only for old aluminum tanks and not designed for steel. Yours are in a high suspect position to be the bad alloy that luxfer stopped using in (i believe) 89’. The bad alloy is still usable as long as it passes hydro, ve and viz, but is susceptible to sustained load cracking that could be catastrophic when filling… (the ve test is best at noticing those cracks before the tank becomes a bomb)

 

[Ulfhedinn]

I suspect you felt old silicon grease in the threads, that stuff is hard to clean out/off. Most shops use an O2 safe lube on everything nowadays to avoid having two sets of tools and such (like interior vip lights). The silicon of yesteryear can really built up over time, usually you just wipe out the excess with a paper towel on your finger - it tends to be dark grey after years of contact with aluminum.

If there is no oily film inside the tank and not globs of grease in the threads I wouldn't worry about it.

Your hydro shop is not a good one if they are VE stamping steel 72s.

I will stop in this week and ask whats the deal.

 

[Scared Silly]

The water in the hydro test can be dirty. The shop I used for some time did many o2 cylinders so their water was clean. And by default all cylinders got o2 cleaned.

 

[Ulfhedinn]

The water in the hydro test can be dirty. The shop I used for some time did many o2 cylinders so their water was clean. And by default all cylinders got o2 cleaned.

That would have been a plus. My shop is on vacation this week (Unbeknownst to me). So hoping to drop in first of next and ask some questions.