From time to time VALVEmagazine.com will open up the archives and re-publish some of our most popular articles from years past. This first appeared on April 25, 2017.
In October of 2016, the Chemical Safety Board (CSB) released its findings into the tragic 2013 explosion and fire at the Williams Olefin Plant in Geismar, LA that killed two workers and injured 167.
The incident occurred during non-routine operational activities that introduced heat to the reboiler, which was offline and isolated from its pressure relief device. The heat increased the temperature of a liquid propane mixture confined within the reboiler, resulting in a dramatic pressure rise within the vessel. The reboiler shell ruptured catastrophically, causing a boiling liquid expanding vapor explosion and fire (Figure 1).
The CSB investigation revealed deficiencies in the plant’s safety culture that resulted (among other things) in failure to manage appropriately or review effectively two significant changes. These changes introduced new hazards involving the reboiler that ruptured. The first was installation of block valves that could isolate the reboiler from its protective pressure relief device. The second was the administrative controls Williams relied upon to control the position (open or closed) of those block valves.