Thu Jul 16, 2015 10:30 am
Considering the possibility of cracking, a surprising number of people still use the 6351 cylinders. Personally, I don't want to take the risk, however small it might be. I sold thirteen of them for scrap even though a friend in Belize wanted to pay more for them, and have them shipped there. I know that they would have been abused and neglected there, and just wouldn't do it.
Most shops here won't fill them, but I still know a at least three that seem to think they are ok, and still use them in their class/rental stock.
For the latest info on testing them I just spoke with the manager of Cylinder Services, probably the largest hydro facility in north Texas. I had heard that they no longer tested pre-1990 aluminum cylinder, but he clarified that rumor, stating certain DOT exemption numbered cylinders were still ok to test. He sent me an email saying that they will only test ones with the following exemption numbers:
"Hello Bill, here are the exemptions that are allowed by the DOT...
6498, 7042, 8107, 8364, and 8422. If you have any question please fill free to call."
He also stated that they perform Eddy Current Testing on all pre-90 aluminum cylinders.
The older I get the better I was.