Whether it’s a diesel engine fire pump or an electric motor, a reliable power source is critical to the proper operation of your fire protection system. Power outages can occur due to scheduled maintenance, storms, or even fire, making it important that you have a backup source of fuel available. Diesel engines are a great option for this. These engines are fueled from local, on-site storage and can operate in emergency conditions when normal power is unavailable.

NFPA 20 requires that the diesel fuel tank be located within the fire pump room, with a dedicated fill and vent port(s), and a visual, monitored fuel level gauge. The tank should be sized to maintain full capacity at the maximum demand of the fire pump system for a minimum of 30 hours. The tank should be refilled regularly to avoid the fuel from becoming stale and unusable.

In addition to the fuel tank, the fire pump system diesel engine needs a water supply to cool the heat exchanger. The cooling water is typically supplied from the fire line piping, but can also be provided by an internal pump recirculation loop. It is important to ensure that the fire line piping and internal pump recirculation loop are sized to provide adequate cooling to the diesel engine.

Other system components include the electric and jockey pumps, manual isolation valves on the water lines, a fire pump test pressure relief valve, packing drip drains and air release valves. The exhaust system consists of a muffler and exhaust piping that is properly pitched (1/4″ per foot) and terminated to the floor drain or frost-free location.diesel engine fire pump