You’re right, the dive industry did instigate the yearly VIP (Visual Inspection Program) on scuba tanks. But it was done as a matter of safety to protect everyone involved. Yearly VIP’s aren’t done in any commercial places like welding supply stores or even fire stations. Why? First, dive shops are kinda lackadaisical, the personnel can be very aloof and un-regimented and all those kind of descriptions. I worked in one for ten years, I know, I saw it.
But a couple of reasons were industry caused. A lot of dive shops and dive sites used to set tanks in a tub of water to keep them cool while the “jammed” air into them. There were occasions where the fill whip got dunked into the tank and the careless “jug jammer” didn’t crack the valve to blow out the water in the connection fitting. So where did the water go, into the tank. It doesn’t take much water inside steel or aluminum tanks to get the corrosion process started. Another way water got into scuba tanks was poorly maintained compressor filtration equipment. Once the molecular sieve is saturated, the moisture goes down stream to the scuba tank or their bank bottles.
So they instituted an industry policy to cover their piss poor performance, at your expense.
Not trying to pat myself on the back but at the shop I worked part time at for ten years, I made it my job to keep the compressor and filtration and everything to the fill whip in good operating order. I went to Florida for a week to attend a class to learn our brand of compressor from daily maintenance to total rebuild on my dime.
The safest way to fill tanks is in a containment cabinet. While in Florida at the compressor school they had a cabinet on site that was a test. It’s a two tank cabinet. One tank is in the cabinet (scba at 4500psi) and the other one next to it, separated by a divider, is being filled. The burst disk was triple disked so it would not blow. They start pumping air into until it explodes. The requirement to pass the test is that the other tank cannot be damaged. It was still in the cabinet. The cabinet looked like a typical paint thinner one gallon gan that was shot with a bullet, totally bulged, unable to be opened. Problem is for the local dive shop, they are quite expensive. Not all but many fire stations have them, because the tax payer pays for them.
