It’s a third party that inspects an item to ensure it complies with applicable regulations for its use. I know AiH has(d) kegs that were from a manufacture that has since been certified, but they are moving the old stock out before new stock.
My opinion only: I think it’s more of a “feel good” for those concerned. I’m not familiar with the NSF certification but assuming the NSF certification is for use as a pressure vessel rated to X pounds. The steel and welds would be tested as such, if it’s a non automated welding process, there is the possibility the person welding could have a “bad day” producing one bad keg. NSF certification cannot prevent “operator error”.
However the fact that the manufacturer went through the trouble of getting it certified which includes periodic inspections/sampling, does go a long way to put my mind at ease that they are producing and want to produce a quality product. In other words it’s not just some schmuck welding tanks in his garage.
Worth a few extra bucks to me, but I would not worry about it either.
Can you trust anything from China to not be a forgery? Since they’ve been caught putting toxics in toothpaste, drywall and pet treats, I’ll stick with Italian, Indian, or used American tanks before I’ll buy Chinese. Just, one biggot’s opinion.
