An Oven Explosion: Lessons Learned on PSM Applications

An explosion occurred at one of our customer's locations in late 1998 involving unburned and partially burned natural gas while the unit was in high fire mode. Investigation of the incident led to many contributing causes, most of which can be categorized broadly as lack of process safety information, failure of a fuel combustion control system, contractor control and lack of management of change. Combustion systems are found throughout all industries and homes. Code-based safeguards are thoroughly and adequately described in NFPA. But is the spirit and intent of the code always applied and interpreted safely? Instrumentation application and installation are similarly well described in manufacturer's literature and the ISA standards. But are these systems installed and arranged properly? Is it important to manage change in something as mundane as fuel fired equipment? Is explosion venting on industrial ovens a sound way to limit damage? Is it even possible in all instances? Are There alternatives? This article highlights the investigation activities, answers these questions, presents conclusions and suggests remedies while showing the applicability of PSM concepts to industries other than the CPI. This article will describe, in general terms: the process, critical changes in design, key components involved, applicable codes, discoveries during the investigation and solutions deployed during the rebuild to address these issues. (C) 2009 American Institute of Chemical Engineers Process Saf Prog 29: 87-93, 2010