In modern building fire protection design, indoor hydrant system and automatic sprinkler system are two core fire extinguishing facilities, and their linkage mechanism is directly related to the efficiency and safety of fire fighting. This article systematically explains the linkage mode and implementation path of the two from the dimensions of technical principles, linkage logic, equipment coordination, etc.
The linkage between the two needs to rely on the fire alarm system (FAS) and the fire linkage controller (FACU). When the pressure switch of the wet alarm valve of the automatic sprinkler system is activated (water flow pressure ≥ 0.05MPa) or the water flow indicator feedback signal, the FACU triggers the indoor hydrant pump to start through the preset logic. At the same time, the direct pump start signal (24V DC) of the indoor hydrant button and the logical judgment of the FACU form a double guarantee to ensure the reliability of the system response.
The linkage logic is divided into two layers: "pressure trigger" and "manual confirmation". When the automatic sprinkler system is started, the FACU will first start the indoor hydrant pump directly according to the pressure switch signal; if the pressure signal fails, it will be started through the "AND" logic combination of the water flow indicator and the regional fire detector. In addition, the manual signal of the indoor hydrant button can be used as a supplement to independently trigger the start of the pump group to avoid linkage failure due to automatic system failure.
Key equipment includes indoor hydrant pump control cabinet, FACU input/output module and pressure switch. The indoor hydrant pump control cabinet needs to be configured with dual modes of "interlocking control" and "linkage control": interlocking control directly starts the pump through the pressure switch or indoor hydrant button without FACU intervention; linkage control remotely starts and stops through the hard-wired signal of FACU (such as DC24V relay contact). The hardware configuration must meet the anti-interference and reliability requirements of the "Fire Linkage Control System" (GB16806-2006).
To prevent water interference between the two systems, the specification requires that the pipe network be separated before the alarm valve group (water flow direction), and only the fire water pump and water supply main pipeline are shared. For example, a high-rise building adopts the scheme of "sharing fire pumps and separating the pipe network before the alarm valve". Through independent ring pipe networks and partitioned pressure reducing valve groups, it ensures that the indoor hydrant system and the automatic sprinkler system do not interfere with each other, while reducing equipment investment and maintenance costs.
The pressure-stabilizing pump plays the role of "pressure buffer" in the linkage. When the indoor hydrant is turned on and the pipe network pressure drops, the pressure-stabilizing pump automatically replenishes the pressure to the set value (such as 0.3MPa) to avoid frequent start and stop of the fire pump. If the pressure continues to drop to the fire pump start threshold (such as 0.2MPa), the fire pump is automatically put into operation. This mechanism can extend the life of the equipment and reduce energy consumption.
In the case of fire emergency, manual operation has a higher priority than automatic linkage. The manual pump start signal of the indoor hydrant button can bypass the FACU to directly start the fire pump, ensuring system reliability in extreme cases. At the same time, a manual control panel is set in the fire control room, allowing operators to directly start and stop the fire pump through hard lines to achieve human-machine collaborative control.
The linkage test needs to verify the transmission accuracy of signals such as pressure switches, water flow indicators, and indoor hydrant buttons, as well as the correctness of FACU logical judgments. Maintenance points include: regularly checking the interlocking/interlocking mode switching function of the indoor hydrant pump control cabinet to ensure that the pressure switch contacts are free of rust; testing the automatic pressure replenishment performance of the pressure regulating pump to avoid false operation due to pressure fluctuations; verifying the anti-interference ability of the FACU input/output module to prevent electromagnetic interference from causing false linkage.
The linkage between the indoor hydrant system and the automatic sprinkler fire extinguishing system is an important manifestation of the integration of fire protection technology. Through scientific design logic, reliable hardware configuration and rigorous testing and maintenance, the two systems can achieve seamless coordination in fire scenarios, providing double protection for building fire safety. In the future, with the integration of the Internet of Things and artificial intelligence technologies, the linkage mechanism will develop in the direction of intelligence and adaptation, further improving the level of fire prevention and control.
