Every now and then you get reminded how Hazards can affect you.
This incident occurred 4 May 2011 on a pipeline project during a hydro-test of new piping.
The fabrication was 24 inch (610 mm) schedule 30 pipe and fittings, 0.562 inch (14.3 mm) wall, and it was being hydrostatically tested when the failure occurred. About 80 feet (24 m) of piping was in the test. The piping was to be pressurised to 2,160 psi (14.9 MPa). At a test pressure of 1,740 psi (12.0 MPa) there was a loud noise, similar to a gunshot.
Four workers were struck by the pressure release. Two were thrown under a truck, One received a bad contusion on his head when he hit the under-carriage of the truck, and the other worker received a severe laceration to his cheek. A third worker lost several teeth when he was hit in the mouth by test equipment which was propelled by the rush of water. Luckily, the fourth worker was not injured.
This is a very sobering situation considering the number of hydro tests administered during Construction. It is very easy to get lulled into a false sense of security after looking at hundreds of hydro & pneumatic tests. It is easy to begin thinking that a thousand tests have passed, so this one will too. It is easy to become complacent with hazards you have in your job every day.
Identify the hazard, assess the risk, control the situation. Every time.