A petroleum refinery experienced a catastrophic rupture at one bank of three heat exchangers in a catalytic reformer/naphtha hydrotreater unit because of high temperature hydrogen attack (HTHA). Hydrogen and naphtha at more than 500F were released from the ruptured heat exchanger and ignited, causing an explosion and an intense fire burned for more than three hours.

The rupture fatally injured seven employees working in the immediate vicinity of heat exchanger at the time of the incident. The workers were in the final stages of a start-up activity to put a parallel bank of three heat exchangers back in service following cleaning. Such start-up activities had resulted in frequent leaks and occasional fires in the past and should have been considered as hazardous and nonroutine. view more

A pressure relief device (PRD) valve failed on a high-pressure storage tube at a hydrogen fueling station, causing the release of approximately 300 kilograms of hydrogen gas. The gas ignited at the exit of the vent pipe and burned for 2-1/2 hours until technicians were permitted by the local fire department to enter the station and stop the flow of gas. During this incident the fire department evacuated nearby businesses and an elementary school, closed adjacent streets, and ordered a high school to shelter in place.

There were no injuries and very little property damage. The corrugated roof on an adjacent canopy over a fueling dispenser was slightly singed by the escaping hydrogen flame, causing less than $300 in damage.

The station's operating systems worked as view more

A significant hydrogen leak occurred during refueling of the onboard hydrogen storage tank of a fuel cell-powered lift truck while it was completely depowered. The in-tank shutoff solenoid valve had recently been replaced, and this was the initial refueling event after the replacement. The fuel zone access panel was removed to allow constant visual leak checking with Snoop leak-detection fluid. The event occurred during the final pressure testing of the repaired system when an O-ring failed at approximately 4500 psi, releasing the entire contents of the hydrogen tank in about 10 minutes. The dispenser hose/nozzle was immediately disconnected, and the leak location was quickly isolated to the tank/valve interface. A 30-foot boundary around the lift truck was cleared of personnel and view more