Fire Pump Tests and Services

The weekly or monthly no-flow (churn) test is an important part of ensuring that a fire pump can be continually relied upon in the event of a fire. These tests will help to ensure that the pump will start and will not overheat in the event of a fire. At an annual frequency, flow testing will be performed to further verify the complete operating condition of the pump.

The no-flow (churn) test of fire pumps must be conducted at either a weekly or monthly basis. The frequency varies by the type of fire pump; diesel and electric; and both have allowances to extend the time between tests based on approved risk analysis.

Generally, diesel fire pumps must be no-flow (churn) tested on a weekly basis.

The requirements for electric fire pumps vary. Most electric fire pumps can be no-flow (churn) tested at a monthly frequency. Electric fire pumps which (1) serve fire protection systems in buildings that are beyond the pumping capacity of the fire department, (2) have limited service controllers, (3) are vertical turbine fire pumps, or (4) those taking suction from ground level tanks or a water source that does not provide sufficient pressure to be of value without the pump all require no-flow (churn) tests at a weekly frequency unless they are provided with a redundant fire pump.

The no-flow (churn) test needs to be conducted by starting the pump automatically. The pump must be started by drawing water from the sensing line to simulate a pressure drop in the system rather than using the “start” button on the front panel of the fire pump controller. An allowance is included in NFPA 25 for an automatic timer using a solenoid valve on the pressure control line.

Electric pumps must be run for a minimum of 10 minutes while diesel pumps must be run for a minimum of 30 minutes.

Qualified personnel must be in attendance whenever the pump is in operation unless automated inspection and testing is completed in accordance with the requirements of NFPA 25. Qualified personnel are defined in NFPA 25 as competent and capable individual(s) having met the requirements and training for a given field acceptable to the AHJ.

NFPA 25 allows the circulation relief valve to open to flow water as a cooling measure. Allowing any additional water flow to prevent overheating is not a requirement of the standard. Flow from the circulation relief valve should be adequate to prevent over-heating of the pump. It should be confirmed that the circulation relief valve is releasing a small amount of water during the no-flow (churn) test. There are additional details around circulation relief valves and main pressure relief valves in NFPA 25 which personnel should be familiar with.

The following visual observations need to be done while the pump is not running.

Record the system suction and discharge pressure gauge readings.

For pumps that use electronic pressure sensors to control the fire pump operation, record the highest and lowest pressure shown on the fire pump controller event log, where such information is available without having to open the fire pump controller.

If the highest or lowest pressure is outside of the normal range, record all information from the event log that can help identify the irregularity.

The following visual observations or adjustments need to be conducted while the pump is running.

Pump system procedure is as follows:

1. Record the pump starting pressure from the pressure switch or pressure transducer

2. Record the system suction and discharge pressure gauge readings

3. Inspect the pump packing glands for slight discharge

4. Adjust gland nuts if necessary

5. Inspect for unusual noise or vibration

6. Inspect packing boxes, bearings, or pump casing for overheating

7. Record pressure switch or pressure transducer reading and compare to the pump discharge gauge

8. For pumps that use electronic pressure sensors to control the fire pump operation, record the current pressure and the highest and the lowest pressure shown on the fire pump controller event log.

9. For electric motor and radiator-cooled diesel pumps, check the circulation relief valve for the operation to discharge water

Electrical system procedure is as follows:

1. Observe the time for the motor to accelerate to full speed

2. Record the time controller is on the first step (for reduced voltage or reduced current starting)

3. Record the time pump runs after starting (for automatic stop controllers)

Diesel Engine system procedure is as follows:

1. Observe the time for the engine to crank

2. Observe the time for the engine to reach running speed

3. Observe the engine oil pressure gauge, speed indicator, water, and oil temperature indicators periodically while the engine is running

4. Record any abnormalities

5. Inspect the heat exchanger for cooling waterflow

In addition to the above, the discharge temperature of the water must be monitored, and the pump shut down if necessary to prevent exposing the pump and/or driver to extreme temperatures.

When the recorded pressure readings on the discharge and suctions gauges show a difference that is greater than 95 percent of the rated pump pressure, the situation needs to be investigated and corrected.

The weekly or monthly no-flow (churn) test is an essential part of ensuring that a fire pump can be continually relied upon in the event of a fire. These tests will help to guarantee that the pump will start and will not overheat in the event of a fire. At an annual frequency, flow testing will be completed to further verify the total operating condition of the pump.