Company Announcements
February 5, 2026
USS schedules restart of Battery #13 at Clairton Coke Works
Written by Kristen DiLandro
U.S. Steel plans to restart Battery #13 at its Clairton Coke Works on Feb. 5, announced the Pittsburgh-based steel producer.
Battery #13 was one of the batteries hot idled since a lethal explosion at Clairton on Aug. 11, 2025. Beginning on Feb. 6, it will resume coke production. USS notified the Allegheny County Health Department to help monitor emissions during the commencement process.
“As we take this step, we continue to hold in our thoughts the employees who were injured or lost during the August 11th incident. We remain mindful of their families, colleagues, and loved ones. Their memory guides our commitment to safety every day,” said the company’s statement.
Since August, USS has hot-idled and restarted Batteries #19, #20, and later Battery #14.
After an investigation, USS found that the use of high-pressure water to flush deposits from routine valve use caused the incident at the Clairton Coke Works. During the process, a sealed cavity inside the valve body was filled with flush water. The water collection then generated excess pressure beyond the valve’s rating.
The pressure 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.
During the investigation, USS identified key updates to its ‘Management of Change’ procedure, which addressed a critical gap in the cleaning procedure.
The Clairton Coke Works, located in the Mon Valley region outside Pittsburgh, is the largest coking facility in North America. Its annual capacity totals 4.7 million short tons. USS opened this coke facility in 1916.
USS also produces coke at its integrated Gary Works in Indiana.
The Clairton plant is part of the larger USS Mon Valley Works complex in Pennsylvania. The complex facilities also include the Edgar Thomson plant in Braddock, the Irvin plant in West Mifflin, and the Fairless plant in Fairless Hills.
