Employees were performing an integrity test of a section of pipe at an oil well. They were bleeding pressure off to a 2-inch line and the valve was already opened. As the inline pipe approached the line to open the valve further, the line parted and separated from the cross section. The cross section was threaded pipe that burst at the threads. The broken piping struck an employee, pushing him 33 feet away and causing fractures to his humerus and tibia.