Findings from the Clairton investigations prompt USS to revise safety protocols  

USS stated that shortly after the incident, it prohibited the use of high-pressure water cleaning. It is reviewing best practices and conducting a review and restructuring of its Management of Change program, for the purpose of “assessing proposed changes in procedures and evaluates risk.” The company said it is reviewing corporate governance documents and updating language to provide more detailed guidelines. The USS spokesperson said the company will provide employee training for all program or procedure changes.

The use of high-pressure water to flush deposits from routine valve use caused the Clairton Coke Works incident. During the process, a sealed cavity inside the body of the valve filled with flush water. The water collection then generated excess pressure beyond the valve’s rating.  

This caused the sudden and complete rupture of the valve body, releasing combustible coke oven gas. The gas accumulated in the transfer area basement and exploded when it reached Battery 14’s ignition source.  

Upon reviewing USS documents, investigators found a process for cleaning valves with low-pressure steam. The documents lacked a procedure for using high-pressure water. Since USS does not currently have an established Management of Change procedure, risk evaluation when switching from low-pressure steam to high-pressure water, the company is addressing the gap.