Preliminary investigations into methods of mitigating hydraulic fluid mist explosions

Many low flammability fluids, such as hydraulic fluids, are known to be flammable, or even explosive, when atomized. Because of the potential hazards involved, a preliminary study was undertaken to investigate the feasibility of using standard fire extinguishing systems and agents to prevent or mitigate hydraulic mist explosions aboard ships. The concept was to apply the agent in the period between the formation of a mist cloud and the initiation of an explosion. Standard potassium bicarbonate-based dry agent (PKP) and carbon dioxide extinguishers and a hand-held water mist system were tested. PKP was found to be very effective in preventing or reducing the severity of the explosions; carbon dioxide had a small beneficial effect and the water mist had essentially no effect.