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Fire pumps are essential components of fire protection systems in commercial buildings and industrial facilities. They are designed to increase water pressure and flow rate in a fire protection system, allowing sprinkler systems and firefighters to combat fires more effectively.

Fire pumps are most commonly driven by an electric motor or diesel engine and are typically located in a separate pump room within a building. They are connected to the water supply system and can draw water from a variety of sources, including municipal water supplies, tanks, or reservoirs. To operate effectively, a fire pump requires a reliable water supply that can provide the required flow rate and pressure and is available at all times. The flow rate and pressure are determined by many factors including, but not limited to, building construction, occupancy, system types and firefighter demands.

In the event of a fire, the fire pump automatically starts and pumps water to the sprinkler system, standpipes, or, in some cases, fire hydrants throughout the property. The increased water pressure ensures that enough water is delivered to the fire with adequate force to effectively control it.

Fire pumps play a critical role in protecting property by providing reliable and effective fire protection. They are subject to regular inspection and maintenance to ensure they are in proper working order when needed.

Reliability issues

Common reliability issues associated with fire pumps include:

• Lack of maintenance: Regular maintenance ensures a fire pump is in proper working order. If the pump is not maintained according to the manufacturer's recommendations, it may fail to operate when needed.
• Power failure: A reliable power source is necessary for electric fire pumps and, in the event of a power outage, a backup generator may be required. Diesel motors rely on batteries to start the motor and can fail due to age and/or lack of maintenance.
• Mechanical failure: Mechanical failure may occur due to wear and tear or improper installation. Bearings, seals, and other components can wear out over time, leading to leaks, reduced flow rates, or other issues.
• Corrosion: Exposure to water or chemicals can lead to corrosion, which may result in leaks or other damages to the pump, ultimately leading to decreased reliability.
• Overheating: Prolonged usage or insufficient cooling can result in overheating, leading to pump damage and decreased reliability.

Coupling issues (that fail/dry out)

Fire pump coupling issues can lead to significant problems, including reduced flow rates, leaks, and pump failure. Common coupling issues associated with fire pumps include:

• Construction: Elastomeric, or plastic, couplings have a higher rate of failure. Since these couplings rely solely on plastic for power transmission, power is completely severed to the pump when they fail.
• Misalignment: Misalignment can occur if the pump and the motor are not properly aligned during installation. Misalignment can cause excessive wear and tear on the coupling, leading to reduced reliability.
• Wear and tear: Couplings, particularly elastomeric couplings, can wear out over time. When a coupling wears out, it can ultimately lead to a pump failure.
• Lack of lubrication: Couplings require regular lubrication to function properly. If the coupling is not properly lubricated, it can cause excessive wear and tear, leading to reduced reliability.
• Overloading: Overloading can occur if the pump is operated beyond its capacity. Overloading can cause excessive stress on the coupling, leading to reduced reliability.
• Improper installation: Couplings must be installed according to the manufacturer's recommendations. Improper installation can cause misalignment, excessive wear and tear, or other issues that can lead to reduced reliability.

Loss prevention activities for couplings include:

• Replace all elastomeric couplings with couplings that have solid connections like pin and bushing, jaw type, or steel grid couplings to prevent coupling issues with fire pumps.
• Ensure proper alignment of the pump and motor during installation and annually during the pump's full flow test.
• Regularly inspect and lubricate couplings, as required.
• Follow all manufacturer's recommendations for installation and maintenance to ensure the reliability of the coupling and the fire pump.

Sample maintenance schedule

Regular inspections and testing can help identify potential issues.

• Any time the pump is running: Be alert for mechanical problems that could create a hazardous condition. Pay particular attention to the diesel pumps cooling water arrangement. Ensure adequate flow through the cooling system by checking the supplied pressure gauge and visually confirming water discharge from the heat exchanger.
• Weekly: Check the engine’s fluid levels (oil, antifreeze).
• Monthly: Check starter battery for continuity between terminals using a digital multimeter. Also check the insulation resistance to ground. Correct any electrical faults.
• Annual: Inspect the electrical wiring harness, electrical terminal connections, and electrical plug-ins for secure, clean electrical contacts, worn or damaged insulation, burnt wires, broken wires, and loose connections. Additionally, ensure proper alignment between the pump and driver.

To ensure the reliability of a fire pump, follow the manufacturer's recommended maintenance schedule, install backup power sources like a Generator Set, and monitor the pump for signs of operating issues before it becomes a major problem. For additional loss prevention and maintenance tips, please see ·´²îæ» publication P8217, Fire Pump Testing and Maintenance Checklist.

Log into the ·´²îæ» Resource Catalog or contact us for copies of the following:

• Understanding the hazard – fire pumps
• Fire pump testing and maintenance checklist