UNITED STATES
DEPARTMENT OF LABOR

Inspection Detail

Inspection: 530858.015 - Elkhorn Construction Inc.

Inspection Information - Office: Englewood

Investigation Summary

At approximately 8:00 a.m. on June 25, 2012, an employee was at the side of the pig launcher. The process was to purge the line of carbon gas with nitrogen. T he nitrogen was pumped by a rig used to frac wells. The pump truck was capable of creating pressures which were several times greater than the launcher was des igned and built for. The employee had several responsibilities some of which we re to check the joints of black pipe feeding the nitrogen. This entailed pourin g soap water on the joints and check for bubbles. He was also responsible for w atching the pressure gauges on the launcher, getting the line purged so the pigg ing operation could start, and opening and closing the ball valves in the line t o provide for proper flow. He had just spoken to another employee while looking at the gauges on the launcher when the launcher ruptured. The ball valve leadin g to the 16-in. main line was not open. The pump truck had been pushing nitroge n into the small pig launcher instead of over three mile long pipeline. The gau ges were not reading any pressure at all and when the pump truck kicked up the p ressure, the launcher ruptured. The launcher was shot over 800 feet away. The main part of the vessel struck another employee killing him instantly. During t he ILI inspection of gas pipeline a pig is used to clean, examine, and test the pipeline. The crew was using a Halliburton pumper truck used for fracing operat ions. The pumper was sending nitrogen down the line to purge the carbons. An e rror in valve positioning occurred when the ball valve was left closed to the ma in line. The pumper truck far exceeded the specs that the pig launcher was buil t to. The launcher ruptured and killed one while injuring two more employees.

Keywords:compressed gas, explosion, flying object, nitrogen, pipe, struck by