[ftc3799]

Update on the exploded tanks, I had time today to do some analysis of the fragments, first of all this is of my own opinion and I have reviewed this with some of my colleagues to confirm my findings. This had nothing to do with the handling of tanks all marks on the tanks came from the parts being scattered across a machine shop floor. It also had nothing to do with temperature the tanks had been at room temperature for a few days. Like most before looking we were thinking damage by over tightening but this was not the case. What I found was a elongated air bubble in the material. The bubble looked like a worm hole around part if the threaded openings base expanding in size and thinning out the threaded wall. My assumption is the fitting stressed the wall enough to open a crack to the bubble that ripped apart when under pressure. When the tank exploded the fragments caused the tank next to it to blow apart.
The one thing I would like to know would be does the manufacturer do any type of vision inspection either by ultrasound or x-ray of the tanks. Because if they don't how many more of these tanks could have hidden rupture points.