Tim, What you are referring to is called "hydrostatic" testing and involves pressurizing the tank with fluid but the tank has to pass a visual inspection first which clearly this one will not pass. I have installed and serviced air compressors and air systems for 30 years and I can assure you no test facility would pass that tank and even if it did pass a pressure test it still would not last long with that much rust, he has said that the darn thing is already leaking through a rust hole! If a tank starts to leak due to rust, as this one has, then it has clearly reached the end of it's service life and must be retired. There simply is no way to repair a rusted out tank and make it safe and to attempt to do so by welding or whatever is extremely risky! Fortunately a leak is all that happens most of the time but an old rusty tank may very well be a time bomb and if you had seen the two tanks I mentioned earlier and the damage that they did to that truck cab and the garage wall you might better understand the dangers involved. The tank in that link posted earlier is only about half the size of the one we are talking about here and it blew at only 100 PSI so one can imagine what a 60-80 gal tank bursting at 135 PSI would be capable of. Both of the tank explosions I examined were due to rust as was the one in the link so yes it does happen and don't bet your life it won't!