A sealed, unclassified electrical control enclosure, part of a listed and certified force-ventilated commercial hydrogen processing unit enclosure, exploded when the equipment manufacturer’s technician pressed the machine stop switch to complete factory commissioning procedure. The technician was forcefully hit by the flying metal panel holding the switch and sustained serious injuries requiring lengthy hospitalization and rehabilitation. Two were hospitalized. Two others were injured. Significant damage to the indoor facility also occurred.

An independent investigation found that drain lines from the external hydrogen vent stack drain trap and the electrical control enclosure cooler/condenser drain were interconnected into a single external sealed floor drain, in a manner not view more

Summary
A hydrogen explosion occurred at a plant, damaging a wall adjacent to the hydrogen storage assembly. The investigation revealed that the explosion was the consequence of deficiencies in components integral to the hydrogen storage assembly, and that this assembly belonged to a supplier contracted to provide hydrogen to the plant. The analysis revealed that had the supplier properly installed and maintained this equipment, this incident would have been prevented. By receiving assurance, on an ongoing basis, that the supplier was properly maintaining this equipment, the company could have also reduced the chance of occurrence of this incident.

Background
A hydrogen supplier was awarded a contract in 1990 to supply the plant with hydrogen as well as to provide view more