if you look back at the posting it makes no difference. If I am wrong, so be it. It had nothing to do with my point... I was talking about welding near tanks that may contain dangerous gases. Oxygen does not have to be one of them.
"Oxygen's most important chemical property is that it supports combustion. That is, it helps other objects to burn. "
"Metal production accounts for the greatest percentage of oxygen use. For example, oxygen is used to burn off carbon and other impurities that are in iron to make steel. A small amount of these impurities may be desirable in steel, but too much makes it brittle and unusable. The carbon and other impurities are burned off in steel-making by blasting oxygen through molten iron.
As i posted, I participated in a project to build an oxygen storage system for a steel-making facility by taking advantage of shut-down windows to perform the necessary tie-ins. Other than those few weeks, the steel plant kept on operating.