Inspection Detail

Inspection: 306372459 - M.J. Welding, Inc

Inspection Information - Office: Denver Area Office

Investigation Summary

On March 31, 2003, Employee #1, a roustabout; Employee #2, a welder; Employees #3 and #4, also roustabouts; were installing an additional tank for crude oil as part of group of steel tanks (tank battery). The existing tanks of the tank battery were used to separate waste water (salt water) from residual crude oil in the salt water. Employee #2 was installing anchor brackets at several locations around the circumference of the base of this additional oil tank. The attachment was completed for one of four anchor brackets that needed to be installed. Welding was nearly completed on the second anchor bracket when suddenly an explosion occurred, which launched the tank approximately 15 feet vertically. At the time of the explosion, Employee #2 and Employees #1 and #3 were positioned immediately adjacent to the tank. Employee #4 was positioned outside the containment berm for the tank battery. Employee #1 suffered fatal injuries and died at the scene. Employee #2 and Employee #3, positioned adjacent to the tank, were hospitalized with serious injuries. Employee #4, positioned outside the containment berm, was hospitalized, treated and released. Prior to welding on the anchor brackets, this additional steel tank had been connected to several pipelines that were already installed and connected to the three existing crude oil tanks. The ventilation pipe had been installed to carry flammable vapors from the headspaces of the existing crude oil tanks to relieve pressure buildup in the tanks. Flammable vapors could flow through the ventilation pipe, which did not have a valve installed, into the tank being welded on. Flammable vapors could not flow out of this otherwise empty tank because all openings, pipe connection and valves were closed.

Keywords: WELDER, EXPLOSION, TANK