September 26, 2017
On Nov. 22, 2016, workers at the ExxonMobil Baton Rouge, La. refinery were preparing isobutane equipment for maintenance.
A spare isobutane pump needed to be placed into service. So, two operators set to work to replace the pump currently in operation.
While removing a malfunction gearbox from a plug valve, the plug valve loosened and came apart, releasing 2,000 pounds of flammable white vapor cloud of isobutane into the atmosphere.
The workers shouted to others in the area, warning them to evacuate. An energized welding machine located roughly 70 feet away ignited the vapor, according to surveillance video.
The resulting fire seriously injured one ExxonMobil employee and three contractors working nearby. According to a report from the Chemical Safety Board (CSB), 15 Emergency responders isolated the release and extinguished the fire about 25 minutes after the initial ignition.
As a result, the CSB conducted a full investigation, discovering “long-standing” reliability issues with gearboxes used to operate plug valves in the refinery’s alkylation unit.
Refinery management did not provide alkylation unit workers performing this operations activity with a written procedure or training on safe gearbox removal from plug valves and its associated hazards, despite it being accepted practice.
In addition, the CSB found that 15 of the 500 plug valves containing manually-operated gearboxes were an older design, which created potential for incorrect removal of the gearbox.
Read more at EHSToday.com
