You would think that freshly made tanks would be in perfect condition. Unfortunately, this is often not the case. And it is the safety of the person filling the tank that is put in jeopardy when an unsafe tank is presented. Each year people die because of unsafe tanks.
When a tank in made certain inspections are done by the manufacturer. But after those are completed there are many opportunities for problems to develop. Tanks are held in storage until sold to a store. They are then shipped, with no valve and no air, by rail or truck. They may be subjected to extremes of temperature, moisture, shock, and other hazards.
Once in the store the tanks are inspected, assembled, and filled. This initial inspection is the most important as it is the first chance to find any problems in manufacturing or transportation.
We often return new tanks to the manufacturer or distributor as defective. Other tanks have to be cleaned before they are suitable for use. I do not know of a reputable dive store that does not inspect every tank before selling it.
We buy our tanks from various sources to minimize the chances of problems. This year (2002) is the first year we have not had to return or clean any new tanks upon receipt.