Understanding and Managing the Often-Ignored Fire & Explosion Hazards of Industrial Air Systems

Although industrial air systems are prevalent, the fire and explosion hazards associated with them are often overlooked.  Air systems provide and distribute compressed air in the range of 10 bar to 20 bar at fixed facilities, offshore facilities, and in mobile equipment.  Compressed air is essential to plants to provide instrument air, pneumatic power, and even necessary mixing or oxygen reactant in some chemical processes.  Ambient air is often compressed and supplied to an air system using an oil-flooded screw compressor.  These machines are ubiquitous in facilities and are often managed through utilities departments.  In our experience, since the machines do not reside in process units, their maintenance and oversight do not often meet the same expectations as process equipment.  Staff perceives these machines as black box equipment and may underestimate or misconceive the potential hazards present.  A loss of oil, cooling water, or cooling air, is normally protected against by pressure and temperature safeguards.  However, it is common for staff, either intentionally or unintentionally, to bypass these safeguards to maintain air supply.  An overview of equipment and associated safeguards commonly used in industrial air systems will be provided.  Possible causes of fires and explosions involving these systems will be discussed through the application of case studies.  Finally, recommendations for reducing the risk of fires and explosions in industrial air systems through preventative and predictive maintenance policies, control and alarm system utilization, and plant management policies will be presented.