Fire Pumps
Water, foam, and gas extinguishing are the three primary methods used to extinguish fires. Pumps are required in water and foam extinguishing methods to spray the extinguisher and provide the required pressure. Pumps used in fire suppression systems are designed differently from standard water pumps. Typical water pumps must operate at high efficiency and low energy consumption for extended periods. The priority for fire pumps is reliability because they are only used during maintenance and tests, except in the event of a fire. Fire pumps must be extremely reliable because even the smallest problem with the pump during a fire can result in significant property and life loss.
The world's leading fire protection standards are those of American origin: UL, FM, and NFPA.
What is UL certification?
UL (Underwriters Laboratories), which stands for "American Insurers Laboratory" and was founded in 1894, is a safety certificate (UL certified). UL is one of the world's largest non-governmental security organizations, operating as an independent third-party testing institute. In the American firefighting market, steering is at the discretion of insurance companies rather than the government. The insurance company accepts this system and lowers the insurance fee if the products used in fire protection systems have a UL certificate. Otherwise, the insurance company will either refuse to insure the building or charge a high insurance fee. Even though numerous insurance companies exist in the United States, UL is widely accepted because it is independent and reliable.
What is FM certification?
FM Global, founded in 1886, is the world's largest insurance company. FM Approvals is a subsidiary of FM Global that certifies products based on FM criteria. FM certification standards are very similar to UL standards but are more stringent and difficult to obtain.
What does "UL/FM approved" mean?
If a "UL/FM" certificate is sought for a project, the "/" here means "OR," implying that the products only need to have a UL OR FM certificate. If FM Global is insuring the project, the products must have an FM certificate. Apart from that, having one of the two approvals is sufficient.
What is NFPA?
The American National Fire Protection Association (NFPA) was founded in 1896. It establishes numerous standards for various products and systems. "NFPA-20" is one of them, and it deals with the design and installation of fire pump sets. The first NFPA standard for automatic sprinkler systems was prepared in 1896. Diesel engines were included in the study for the first time in 1913. To date, NFPA-20 has been renewed 31 times. Every 3-4 years, the standard is renewed. This is due to the development of new technologies, the discovery of new materials, and the analysis of reported fire incidents, which results in new findings.
A typical 'one electric motor + one diesel motor + one jockey' pump set designed to NFPA-20 includes:
- Pump body
- Diesel engine
- Electric motor
- Control panel
- Fuel tank
- Jockey pump
- Coupling and shaft
- Valves
- Flow meter
The standards established by the NFPA apply to the entire system. UL/FM deals with each product in the system separately. If the project requires UL/FM certification, the design must comply with NFPA-20, and all parts within the pump set must be UL/FM certified.
The requirements for UL/FM-approved fire pumps are as follows:
1) 1) The pump's closed valve pressure should not exceed 140% of its nominal pressure. (Hs ≤ 140% x H)
2) The input pressure should be less than 47,7 kilogram/pascal. It should provide at least 65% of the pump's nominal pressure when operating at 150% of the pump's nominal flow rate. (H 1.5 Q ≥ H x 65%)
3) 3) The test is performed at the maximum positive absorption pressure required to capture the pump's maximum brake impulse. (P ≥ BHP)
4) 4) The cutting pressure must not be lower than 99% of the maximum pressure.
Through the piping system, fire pumps deliver water to sprinklers or nozzles to put out the fire. They can be powered by an electric motor, an internal combustion engine, or steam turbines. Sets that only have electric motor pumps need a second power source. This could be a separate generator installed in the building or facility. When the pressure in the Sprinkler system falls below a certain set value, the fire pump is activated. To accomplish this, one or more sprinklers in the system must be exposed to heat and opened. If the main pump is not turned on for any reason, the backup pump will turn on.
Vertical turbine and horizontally split body fire pumps are the two most popular types of fire pumps. The capacity of a fire pump can range from 25 to 5000 gallons per minute. Pressure values vary between 40-394 psi for horizontally split bodies and 26-510 psi for vertical turbine pumps.