Do You Know Knowledge Of Fire Water Supply And Fire Hydrant Systems?

Mar 15, 2023 | news


Rapid industrialization and urbanization have led to the great development of engineering construction, and the fire water supply and fire hydrant systems have also developed rapidly along with the large-scale development of engineering construction. At the same time, more frequent international exchanges have made us better understand fire water supply and fire hydrant systems. The importance of engineering construction, as well as the relationship between safety, reliability, and economy, is safety and reliability first, followed by economic rationality.


Water is the main fire extinguishing agent in the fire fighting process, and its supply directly affects the effectiveness of fire extinguishing. According to statistics, 93% of the cases where fires were successfully extinguished had better fire water supply conditions; while 81.5% of fires where fires were unfavorably extinguished were short of fire water.


The fire water supply is the heart of the water fire extinguishing system. Only when the heart is safe and reliable can the water fire extinguishing system be reliable. The fire water supply system is not used at ordinary times, and its reliability cannot be tested because of its use. Therefore, it is necessary to strengthen the management of its safety and reliability from various aspects such as design, construction, and daily maintenance management.


The fire hydrant is an important fire-fighting facility for firefighters and people in buildings to extinguish fires. People-oriented, more attention should be paid to the combination of the location of fire hydrants and the tactical and technical requirements of firefighters to fight fires, to meet the requirements of the firefighting force’s first dispatch to put out fires.


Relevant regulations on fire water supply and fire hydrant system


The outdoor fire-fighting water consumption of factories, warehouses, storage yards, storage tank farms, or civil buildings shall be determined according to the number of fires at the same time and the outdoor fire-fighting water consumption required for one fire extinguishment.

The number of fires at the same time should meet the following requirements:

  1. For factories, storage yards, storage tank farms, etc., when the area is less than or equal to 100h㎡, and the number of people in the attached residential area is less than or equal to 15,000, the number of fires at the same time should be determined as one; When the land area is less than or equal to 100h㎡, and the number of fires in the attached residential area is greater than 15,000, the number of fires at the same time shall be determined as 2 fires, 1 fire shall be counted in the residential area, and 1 fire shall be counted in the factory, storage yard or storage tank area. 1;
  2. For factories, storage yards, and storage tank farms, etc., when the floor area is greater than 100h㎡, the number of fires at the same time should be determined as 2, and the factory, storage yard, and storage tank farm should be based on the two buildings with the largest water demand (or storage yard, storage tank) each counts as 1 case;
  3. The number of fires in warehouses and civil buildings at the same time should be determined as one fire.
    The design flow rate of fire-fighting water required for fire extinguishing of a fire shall be determined by the building’s outdoor fire hydrant system, indoor fire hydrant system, automatic sprinkler system, foam fire extinguishing system, water spray fire extinguishing system, fixed fire monitor fire extinguishing system, fixed cooling water system, etc. The design flow composition of various water fire extinguishing systems, and shall meet the following requirements:
  4. It should be determined according to the sum of the maximum design flows of various water fire extinguishing systems that need to act at the same time;
  5. When the fire water supply system is shared by two or more buildings, it shall be determined according to the one with the largest design flow;
  6. When the fire water supply is used together with the domestic and production water supply, the design flow of the water supply for the combined system should be the sum of the design flow of the fire protection water supply and the maximum hourly flow of domestic and production water. When calculating the maximum hourly flow of domestic water, the shower water consumption should be calculated as 15%, and the water consumption that can be stopped in cases of fire such as watering and washing can be ignored.
    General requirements for fire water sources
  7. Within the scope of urban and rural planning areas, the municipal fire water supply should be planned, designed, and implemented simultaneously with the municipal water supply network.
  8. The water quality of fire-fighting water sources should meet the functional requirements of water fire-fighting facilities.
  9. Firewater sources should meet the following requirements:
    ①Municipal water supply, fire pools, natural water sources, etc. can be used as fire water sources, and municipal water supply should be used;
    ②Rainwater clear water pools, reclaimed water clear water pools, water features, and swimming pools can be used as backup fire water sources.
  10. The pH value of the water usually filled in the fire water supply pipeline should be 6.0-9.0.
  11. Anti-freezing measures should be taken for fire pools, water towers, and high-level fire pools in freezing areas such as severe cold and cold winters.
  12. When rainwater clear water pools, reclaimed water clear water pools, water features, and swimming pools must be used as fire-fighting water sources, there should be technical measures to ensure that the water quantity and quality required by the fire-fighting water supply system can be met under any circumstances.
    water supply facilities
    Fire Hydrant
  13. The type of fire pump should be determined based on comprehensive factors such as reliability, installation site, fire water source, design flow rate, and lift of fire water supply. The drive of water pump should be directly driven by an electric motor or a diesel engine. The fire pump should not use dual motors or diesel engines. Composed of dual power-driven water pumps.
  14. The fire-fighting water pump unit should be composed of water pumps, drivers, and special control cabinets; a group of fire-fighting water pumps can be composed of working pumps and standby pumps of the same fire-fighting water supply system.
  15. Manufacturers of fire pumps should provide a complete performance curve of pump flow and head, and should indicate parameters such as flow, head, cavitation allowance, power, and efficiency.
  16. The minimum rated flow rate of a single fire pump should not be less than 10L/s, and the maximum rated flow rate should not be greater than 320L/s.
  17. When the fire pump adopts a centrifugal pump, the type of the pump should be comprehensively determined based on factors such as flow rate, head, cavitation allowance, power and efficiency, speed, noise, and environmental requirements of the installation site.
    Selection of fire pumps
  18. The performance of the fire pump should meet the flow and pressure requirements of the fire water supply system;
  19. The power of the driver equipped with the fire pump should meet the requirements of the power required for operation at any point on the performance curve of the selected pump’s flow and lift;
  20. When using a fire pump driven by a motor, a fire pump with a dry installation of the motor should be selected;
  21. The flow head performance curve should be a smooth curve without humps and inflection points. The pressure at zero flow should not be greater than 140% of the design working pressure, and should be greater than 120% of the design working pressure;
  22. When the outlet flow is 150% of the design flow, the outlet pressure should not be lower than 65% of the design working pressure;
  23. The sealing method and material of the pump shaft should meet the requirements for the fire pump to operate at low flow;
  24. The fire water pump models of the same pump group for fire water supply should be consistent, and the number of working pumps should not exceed 3;
  25. When multiple fire pumps are connected in parallel, the influence of flow superposition on the outlet pressure of fire pumps should be checked.
    The main material of the fire pump
  26. The pump shell should be ductile iron;
  27. The impeller should be bronze or stainless steel.
    When the diesel engine fire pump is used, the following requirements shall be met
  28. Diesel engine fire pump should adopt compression ignition type diesel engine;
  29. The rated power of the diesel engine should check the influence of altitude and ambient temperature on the power of the diesel engine;
  30. The diesel engine fire pump should have performance of the continuous operation, and the test running time should not be less than 24 hours;
  31. The storage battery of the diesel engine fire pump should ensure that the fire pump can be started automatically at any time;
  32. The fuel supply tank of the diesel engine fire pump should be determined according to the duration of the fire, and the minimum effective volume of the fuel tank should be configured according to 1.5L/kW, and the fuel stored in the fuel tank of the diesel engine fire pump should not be less than 50% of the reserve.
    The fire water pump should meet the following requirements
  33. The fire pump should adopt self-priming water absorption;
  34. When the fire pump pumps water directly from the municipal pipe network, an air-block backflow preventer should be installed on the outlet pipe of the fire pump;
  35. When there is no suction well at the suction port, a swirl preventer should be installed at the suction port.