The main purpose of the water pump adapter is to supply water from the outdoor fire hydrant for fire trucks when the indoor fire pump fails or in case of a large fire.
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1. The installation method of the water pump adapter on the fire zone
According to the regulations of "High Regulations", each partition within the water supply pressure range of the fire truck must be equipped with a water pump adapter. In the past, it was thought that the part of the building with a height of more than 50 m could not be helped by fire trucks. It is possible to consider not installing a water pump adapter. However, with the development of fire fighting technology and equipment, many cities have been equipped with high-power fire trucks, and the fire water supply is far away. If it exceeds 50m, 50m should no longer be used as the limit of whether to set up a water pump adapter.
When the fire protection system is divided vertically, the settings of the water pump adapters in each district can be considered to be combined, and there is no need to set them separately. In some designs, the water pump adapter is installed in front of the pressure reducing valve to artificially reduce the water supply height of the city fire truck. This may cause the pressure of the fire protection system on certain floors to be satisfied, but it cannot be satisfied after decompression. , It is very detrimental to fire extinguishing.
For the low-zone fire hydrant system, the lower part of the low-zone fire hydrant is a pressure-reducing and stabilizing fire hydrant, while for the low-zone self-spraying fire-fighting system, the lower part of the low zone is equipped with a pressure-reducing and stabilizing valve. In addition, the low-zone pipe network is under pressure The capacity can also be increased to 1.6 MPa or 2.5 MPa according to the height of the building. At present, the multi-stage pump head of the large and medium-sized city fire trucks is 1.12 ~ 1.37 MPa, so the low-zone water pump adapter is not installed after the pressure reducing valve. There will be overpressure problems. The water pump adapter for each zone can be set with a check valve to prevent the pressure in the high zone from being transmitted to the low zone.
2. Setting in the sprinkler fire fighting system of the water pump adapter
In the sprinkler system, the water pump adapter can be directly connected behind the wet alarm valve. When the fire truck arrives at the scene and delivers water to the indoor sprinkler fire-fighting pipe network through the water pump adapter, the fire is known, and there is no need to start the pressure relay and hydraulic alarm bell again, nor to start the fire-fighting water pump and other facilities again.
3. The distance between the water pump adapter and the fire pool
According to the requirements of fire protection regulations, the distance between the water pump adapter and the outdoor fire hydrant or fire pool should be 15-40m. The fire-fighting pool should store all the indoor and outdoor fire-fighting water consumption during the fire-fighting period (if there is a reliable water supply source, that is, when the building has two-way water supply in the city, the fire pool can be considered to subtract the replenishable part). At this time, the outdoor fire hydrant is only Auxiliary backup measures. In this case, the distance between the water pump adapter and the fire pool should be controlled within 15-40m, otherwise it will be difficult to get water. In addition, considering the turning radius of the fire truck, the distance between the water pump adapters should not be too close, otherwise the fire truck will interfere with each other when taking water. This creates a pair of contradictions: assuming that the flow rate of each pump adapter is 10-15L/s, if the indoor fire hydrant water consumption is 40 L/s, the building with a self-spraying firefighting water consumption of 26L/s needs to be installed. It is not easy to set the water pump adapter, plus the engineering conditions. It is not easy to make the distance between the water pump adapter and the fire tank not exceed 40m, and the distance between them cannot be too close.
How to solve this problem? The author proposes to set up special fire-fighting circular pipes outside the building and install outdoor fire hydrants on it. The distance between one of the outdoor fire hydrants and the water intake of the fire pool should not exceed 40 m. The vehicle can take water from the water intake and supply it to the outdoor fire-fighting pipe network; similar to the relay method, the fire-fighting vehicle takes water from other outdoor fire hydrants and supplies it to the building through the water pump adapter. An anti-pollution air shut-off valve should be installed on the municipal water supply pipe to prevent the backflow of fire fighting water from polluting the municipal water supply network. In this way, in the event of a fire, if the municipal pipeline is damaged, the outdoor fire hydrant can still function, and the distance between the water pump adapter and the water intake or outdoor fire hydrant can be controlled within the range of 15-40m.
Fourth, the relationship between the water pump adapter and the number of outdoor fire hydrants
According to the fire protection regulations, the number of outdoor fire hydrants is determined by the outdoor fire water consumption, and the water consumption of each outdoor fire hydrant is 10-15L/s; the water pump adapter is based on the sum of the indoor fire water consumption of the indoor fire hydrant water supply system and the water consumption of the automatic sprinkler system To be sure, the flow rate of each water pump adapter is also calculated at 10-15L/s. When the indoor fire fighting water consumption is greater than the outdoor fire fighting water consumption, the number of outdoor fire hydrants is less than the water pump adapter. When the indoor fire fighting water supply system fails during the fire, the water pump adapter needs to be completed from the outdoor fire pool or outdoor fire hydrant. The task of transferring all indoor fire-fighting water consumption, so the number of outdoor fire hydrants should be determined according to the number of water pump adapters, and there should be a one-to-one correspondence between outdoor fire hydrants and water pump adapters. In addition, the number of water intakes in the fire tank should be no less than two, so that the number of outdoor fire hydrants can be reduced.
5. About the setting of the safety valve
In order to prevent overpressure in the fire-fighting pipeline, a safety valve should be installed in the fire-fighting system. When the fire hydrant and sprinklers are not turned on, if the fire pump malfunctions, or there are only a few fire hydrants and sprinklers open at the beginning of the fire, that is, when the flow is zero or very small, a high-lift situation will occur, and the system may be overpressured, resulting in Broken pipe. The author recommends that the water pump adapter adopts the style with a safety valve inside, which can save pipe fittings, and make the entire fire protection system safe and reliable, and prevent overpressure in the pipe network.
