Hi Greg,
I’m a PSI/PCI inspector and all the info is within their course curriculum.
1. Is a myth as long as the tank has visible markings and can pass hydro and vis it may be put into service.
2. This applies only to Luxfer aluminum made prior to June 30 1988 and the reason is cost of upkeep. These are the only tanks that require Eddi current testing with each Visual inspection. If they pass both tests and are up to date on hydro they can be put in service. They are made with a alloy (6351) who’s molecular characteristics make them more susceptible to cracking at points of machining(the neck)
3. This refers to a spray in liner or coating that manufacturers used inside steel tanks in the past. Most will deteriorate with time and could cause regulator failure. These tanks could be tumbled with abrasive media to remove the liner but they will often deteriorate rapidly after making the effort without merit.
4. Eddi-Current testing may be used on any aluminum tank which the inspector suspects of neck fractures. There is no blanket requirement for Eddi-Current due to tank age. The only blanket requirement is due to 6351 alloy type and this is only found on the Luxfer tanks and stated above.
If you need more info you can call PSI/PCI as they are the authority on the subject