Initial cement truck tank explosion and worker leg amputation

First in-plant failure of the cement truck tank line. Worker lost a leg during pressurization testing with 100 PSI air instead of water. Company paid insurance and continued production without investigation. The setup case for the fatal Pennsylvania failure.

When they built these things, they actually pressurized them to 100 PSI — with air. Dumb. If something's liable to fail, you don't pressurize with air on a test, you pressurize with water, because if water fails it goes splat. If air fails, it goes kaboom and blows up your building. You'd be surprised, with a 200-gallon tank, how much energy. You can calculate it by integral P dV — it's a lot of energy. It would blow up the building. They had one fail and a guy lost a leg in the plant. These rocket scientists didn't even worry about it. They paid the insurance on the guy's leg and kept making them. They didn't look into why it had failed. They didn't know they were supposed to have a doubler plate.