Process Safety Progress, Vol.21, No.2, 142-150, 2002
Common causes and corrections for explosions and fires in improperly inerted vessels
In this article, causal factors and corrective actions surrounding improperly inerted vessel incidents are developed and compared based on several case studies of flash fires or explosions involving these process vessels. In industry, vessels that contain or have contained flammable vapors are commonly inerted for many reasons, but one of the most common is explosion prevention. Common inerting gases are carbon dioxide, nitrogen, steam, and air, depending upon the specific application. Incident causes ranged from procedures to design issues, but a general set has been produced for application to the problem of explosion prevention in process vessels. Each case study is compared to safety standards to show how safe work practices could have prevented the accidents. However, rigid adherence to safety standards may not be sufficient to prevent an accident. The application of a safety standard should be tempered by situation-specific circumstances. Some specific recommendations for preventing explosions include methods for improved mixing of the inert gas, the use of blinds, filling the vessel with water, improved work procedures and improved monitoring procedures. A suggested design strategy for engineering an inerted system is presented.