Contributor: Andy Aleksich, Senior Designer of F.E. Moran Special Hazard Systems
Writer: Sarah Block, Marketing Director of The Moran Group
In the summer of 2013, a coal-fired power plant needed to conduct maintenance work on a conveyor belt. The maintenance personnel shut down the fire sprinkler system to avoid any accidental activation during welding. The sparks ignited the coal residue on the conveyor belt. The fire grew and pieces of the burnt conveyor belt fell 180 feet onto a stack of coal, which subsequently caught fire. The total cost of this fire was $1 million.
In the late fall of 2013, a steel plant maintenance crew turned off the water supply to the deluge header for fear of freezing. A fire sparked and found its way into an electrical arc furnace. It shot the fire up three floors, burning equipment, property, and injuring five workers. The fire cost millions of dollars.
What do these events have in common? In both instances, the fire sprinkler system was taken offline unsafely. Fires like these occur weekly in circumstances where the fire sprinkler system was taken offline, allowing the fire to grow out of control. When a fire sprinkler system is working and maintained properly, it is 96% effective in containing the fire, according to the National Fire Sprinkler Association. There are occasions where fire sprinkler water supply needs to be shut down, but there is a safe way to do it. Here are our tips for safely taking a fire sprinkler system offline.
Stop all hazardous activities in the affected area. In the first example above, we see that the coal-fired power plant shut down the fire sprinkler system for maintenance on the conveyor equipment. However, during the maintenance activity, welding and cutting were performed in a coal-handling area. These are very hazardous activities and never should have occurred with the fire sprinkler system offline.
If a fire sprinkler's water supply needs to be turned off, do it with fire protection in mind. Place a roving fire patrol or stationary fire watch in the area to fight a fire in case it ignites; position adequate firefighting equipment in the area of concern. In addition, do not forget to contact local security and the central alarm station to avoid a false alarm.
Always have a professional bring the fire sprinkler system on and offline. To bring a fire sprinkler system offline, close the water supply control valve and open the main drain valve. The auxiliary and inspector valves should be open. System and pressure gauges should be at zero. Make sure all water is drained completely. Ensure a LOTO program is in place to provide a pressure barrier control for work activities, and make sure the system is put back in service as soon as possible.
To place the valve back in service, a fire sprinkler professional should be called. Each type of system has its own procedures to bring back online. In addition, tests and inspections should be conducted to make sure that the system is working properly once it is back online.
Fire sprinklers are a necessity in power, chemical, and industrial plants. With extremely hazardous conditions and an abundance of fuel, no chance should be taken when taking your fire sprinkler system on and offline. Be safe and follow proper procedures to protect people, plant, and production.