Fire pumps are a critical component of many sprinkler systems. The moment sprinklers are activated, the pressure in the system can drop significantly and the fire pumps are needed to maintain the pressure enough to keep the water flowing.
Fire pumps are designed to quickly deliver sufficient water to douse a fire before it has a chance to spread. Fire pump intakes are connected to underground public water supply piping, or a tank or reservoir, to provide water flow at a higher pressure to the sprinkler system risers and hose standpipes.
The only way to know if fire pumps will function properly when needed is to inspect and test them regularly in accordance with Chapter 8 of the National Fire Protection Association (NFPA) 25 Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection.
This post provides a good summary of the most important requirements for electric motor-driven and diesel engine-driven fire pumps, which are the most common types of fire pumps in use today. Generally, there are more regulations for diesel drives than electric ones due to the accommodations necessary to handle the fuel system, cooling, exhaust, vibration, etc.
Weekly Inspection & Testing Requirements
Both diesel and electric pump systems must be inspected weekly along with the pump itself and the pump house or room. Diesel engine-driven fire pumps must also be tested weekly, while electric motor-driven pumps may be tested weekly or monthly.
The pump house, pump system, and the electrical system that powers it should all be visually inspected on a weekly basis.
What to Look for When Inspecting Your Pump House
The primary concern in the pump house is the temperature. The pump house should be checked weekly to ensure it has adequate heat.
For pump rooms that house an electric motor or diesel engine pumps with engine heaters, the temperature should be at least 40°F (4.0°C). However, if your fire pump uses a diesel engine without an engine heater, the pump room temperature should be maintained at 70°F (21°C) to ensure its operability. An engine jacket water heater can be used if the required temperature cannot be maintained.
While checking the temperature each week, you should also check to ensure that all ventilating louvers are free to operate and that there is no water pooling anywhere on the floor.
Inspection and Testing Requirements for the Pump and Its Electrical System
Weekly inspections of your fire pumps and its electrical system are essential to ensuring its ongoing reliability and performance. One of the most important tests required by NFPA 25 is the weekly no-flow or “churn” test, during which the pump must be operated at a no-flow condition. Requirements for this type of testing differ depending on the pump type.
Diesel Engine-Driven Pumps
No-flow testing is required weekly unless a risk analysis indicates a different frequency is acceptable. For diesel engines, the engine must be run at the rated speed for at least 30 minutes to allow all the components to warm up and stabilize.
Electric Motor-Driven Pumps
The following types of electric motor-driven fire pumps must be tested weekly:
- Fire pumps with limited service controllers
- Vertical turbine fire pumps with vertical turbines
- Fire pumps taking suction from ground level tanks or a water source that does not provide sufficient pressure to be of material value without the pump
Additionally, any electric motor-driven fire pumps used in buildings beyond the pumping capacity of the fire department must also be tested weekly.
A monthly test frequency shall be permitted for other types of electric fire pumps or for pumps systems with a redundant fire pump. As with a diesel system, more infrequent testing may be allowed if a risk analysis indicates a different frequency is acceptable.
For no-flow testing on electric fire pumps, the pumps must be allowed to run for at least 10 minutes.
In addition to the weekly churn test, there are a number of other weekly inspection and testing requirements, which are summarized in Table 1.
Table 1: Requirements for weekly inspection and testing for fire pumps and their electrical systems.
| Component | Required Inspection/Test |
| Pump System | |
| Pump suction and discharge and bypass valves | Check to ensure these valves are fully open. |
| All piping | Look for any signs of leaks. |
| Suction line pressure gauge | Check pressure to ensure it is within the acceptable range. |
| Suction reservoir | Ensure the water inside the reservoir is at the proper level. |
| Wet pit suction screens | Make sure these are in place and unobstructed. |
| Waterflow test valves and hose connection valve | These valves should be closed. |
| The line to test the valves | The line should be free of water. |
| Coupling guard | Ensure that the guard is in place. |
| Electrical System | |
| Controller (power on) and transfer-switch normal pilot lights | Both should be illuminated. |
| Isolating switch for the standby (emergency) source | The switch should be closed. |
| Reverse phase alarm pilot light and normal phase rotation pilot light | If the system is equipped with a reverse phase alarm pilot light, the light should be off; if equipped with a normal phase rotation pilot, the light should be on. |
| Oil in the vertical motor sight glass | Check the level to ensure it is within the acceptable range. |
| Maintenance (jockey) pump | Check to see that it has power. |
Additional Requirements for Fire Pumps with Diesel Engines
If your fire pump is powered with a diesel engine, you should also check the components shown in Table 2 during your weekly inspections.
Table 2: Requirements for weekly inspection and testing specific to diesel engines used in diesel engine-powered fire pumps.
| Diesel Engine Component | Required Inspection/Test |
| Fuel tank | Refill if less than two-thirds full. |
| Controller selector switch | The switch should be in the auto position. |
| Valve in the fuel supply lines from tank to driver filter or pump system | These should be locked in the open position. |
| Batteries | Take at least two voltage and charging current readings for each battery. At least two readings for voltage and charging currents each must fall within their acceptable ranges. |
| Battery pilot lights or battery failure pilot lights | If the system is equipped with a battery pilot light, the light should be on; if equipped with a battery failure pilot light, the light should be off. |
| Alarm pilot lights | All alarm pilot light should be off. |
| Engine running time meter | Ensure the meter is operating and has a reading. |
| Oil in right angle gear drive and crankcase | Check the level in each to ensure it is within the acceptable ranges. |
| Cooling system | Check the cooling water level to ensure it is within the acceptable range and clean the strainer if necessary. Also, check to ensure that water flow through the heat exchanger (if present) is adequate. |
| Battery electrolyte | Check the level and specific gravity to ensure they are within the acceptable range. |
| Battery terminals | Check to see if terminals are clean and free from corrosion. |
| Water-jacket heater | Make sure the heater is operational. |
Annual Inspection & Testing Requirements
Annual performance testing is required to ensure your fire pump can provide the necessary amount of water to douse a fire quickly if activated. This requires a flow test, during which water is pumped through a test header and hoses or flow meter, to allow for the necessary performance data to be collected. The data allows for year-to-year comparisons of pump performance. The measurements to be taken include:
Suction pressure, discharge pressure, RPM, volt and amp readings at churn (no flow), rated (rated capacity of the pump) and peak (150% of the rated capacity of the pump) for the purpose of determining the pumps ability to perform as designed.
For diesel engine-driven fire pumps, you should also check the water discharge from the cooling loop to ensure it is adequate to maintain an acceptable engine temperature.
In addition to the annual flow testing, there are a number of other components of diesel-powered and electric fire pumps that must be inspected and maintained at least annually. These are summarized in Table 3.
Table 3: Components of fire pump systems with an annual inspection and testing requirements per NFPA 25.
| Component | Required Inspection/Test |
| Alignment of pump driver | The alignment should be parallel and angular. If not, realignment is necessary. |
| Control and power wiring connections | Check all wiring and connections for signs of cracking and repair/replace as needed. |
| Power transfer switch | Must be tested in accordance with NFPA 110 Standard for Emergency and Standby Power Systems. |
| Printed circuit board (PCBs) corrosion | Look for any signs of corrosion. |
| Batteries | Determine the specific gravity, state of charge and charger rates. The battery for a 12-volt system should have a cranking voltage greater than nine volts. In a 24-volt system, the battery should have a cranking voltage of at least 18 volts. Any corrosion on the terminals should be cleaned off. |
| Fire pump alarm signals | Check to ensure they are functioning properly. |
| Plumbing parts (inside and outside of panels) | Check all plumbing parts, including valves, for excessive wear, damage, or obvious leaks. |
| Pressure gauges and sensors | Inspect and replace/re-calibrate if more than five percent out of calibration. |
| Exhaust system | Check for leakage and drain the condensate trap if necessary. Check any hangers and supports for the exhaust system to ensure they are sound. |
| Circulating water filters | Replace filters at least once a year. |
| Cooling System (diesel engines) | Check the flexible hoses and connections for any cracks or leaks. Check antifreeze levels and top off if needed. Check the high cooling water temperature switch and the cooling water solenoid valve. Check and clean the heat exchanger if necessary. |
| Sacrificial anode | Check the condition of the anode and replace it if necessary. |
| Pump, motor bearings, and couplings | These should be greased at least once a year. |
Additional Annual Testing and Maintenance Requirements for Fire Pumps with Diesel Engines
If your fire pump is powered with a diesel engine, you should also check the components shown in Table 4 at least once a year. By someone authorized to perform annual maintenance on a diesel fire pump drivers.
Table 4: Requirements for annual inspection and testing specific to diesel engines used in diesel engine-powered fire pumps.
| Diesel Engine Component | Required Inspection/Test |
| Fuel | Diesel fuel must be tested in accordance with ASTM D7462 Standard Test Method for Oxidation Stability of Biodiesel (B100) and Blends of Biodiesel with Middle Distillate Petroleum Fuel to determine if fuel is degraded. |
| Fuel tank, tank vents, and overflow piping | The fuel tank should be checked for water and foreign materials. Look for any obstructions in the tank vents and piping. |
| Engine | Measure the back pressure on the turbo and check the engine crankcase breather to ensure there are no obstructions. Observe the shaft movement or end play while conducting flow testing. |
| Engine oil | Engine lubricating oil and the engine oil filter should be changed every 50 hours of operation or annually. |
Let Koorsen Keep Your Fire Pumps in Working Order
With more than 70 years in the business, Koorsen is a leader in the fire protection industry. Our factory-trained and certified technicians install and maintain sprinkler systems equipped with fire pumps and can assist you with all your inspection and maintenance needs and can perform any repairs necessary to keep your system in peak condition. Contact Koorsen today to enjoy the peace of mind that comes with knowing your fire protection systems are compliant and keeping your employees, customers, and property safe from fire.
