Water saving suggestions for stainless steel flange pipes of fire water supply system

　　 For a long time, people think of fire-fighting water systems first. Therefore, from top to bottom, people should establish the awareness of equal emphasis on fire protection system and water saving, and make regulations from the height of the specification, and implement them from the design process.

　　 1. Formulate water-saving regulations for fire water supply systems

　　Like a domestic water system, water-saving regulations related to fire-fighting water systems are formulated as the basis for guiding engineering design and engineering management, so as to achieve the requirements of comprehensive water-saving. For example, it is stipulated that fire-fighting pools can be avoided as far as possible when conditions are available. It is recommended that the system pressurized pump is directly pumped from the urban stainless steel flange pipe network; the upper and lower limits of the flow rate of the fire-fighting water system and the upper and lower limits of the coefficients of the fire pump parameters are strictly regulated; It is stipulated that the fire-fighting water pump adopts a pump type with a gentle head volume curve and so on.

　　 2. Adopt water-saving equipment and take water-saving measures

　　1. Water treatment equipment for fire-fighting pools and fire-fighting water tanks

　　 The water capacity of the fire fighting pool is relatively large. Generally, the water discharged by a fire fighting pool is about 300m3-500m3 on average. Hundreds of thousands of pools in hundreds of cities will have a huge amount of water. Therefore, the water treatment equipment installed in the fire fighting pool and water tank can not only effectively ensure the water quality requirements of the system, but also greatly reduce the number of cleaning and replacement of the pool, and reduce the waste of large amounts of water resources caused by the cleaning and replacement.

　　2. The tangent fire pump with a smooth head volume curve is adopted

　　The big feature of the tangent fire pump is that the pump head changes very little with the flow rate. Therefore, it can ensure that the system pressure is basically constant after the water pump is started, reduce the system pressure shock, make the output flow of the system working state basically coincide with the rated design flow, and improve the efficiency of fire-fighting water use.

　　3, adopt reasonable decompression measures to the system

　　 For high-rise buildings, due to the large geometric height difference between the top and the bottom, the dynamic and static pressure difference between the top and the bottom of the fire protection system is large. That is, the dynamic and static pressures at the bottom of the system are far greater than the dynamic and static pressures at the top. This causes the system to have such a result when it is working: the flow rate of the nozzle or hydrant on the top of the system is basically the same as the design value, while the flow rate of the nozzle or hydrant in the lower part of the system is much greater than the design value. The end result will be that when a fire occurs at the bottom of the building, the water output of the system is far greater than the actual demand, and the water supply in the entire fire duration cannot be guaranteed. This will affect the effective fire fighting of the building fire, and it will not be able to play the role of fire water storage, resulting in Fire water is wasted. The basic measures to solve this problem are: reasonable decompression zoning of the system, or the use of decompression orifice plates, decompression and stabilization fire hydrants on the overpressure floor.

　　4. Reasonably determine the system pipe diameter and pipe loss

　　When calculating the pipe diameter of the system, the system flow rate should be selected reasonably. If the system flow rate is too small, the pipe diameter will be too large and uneconomical; if the system flow rate is too large, the pipe loss of the stainless steel flange system will increase, which will not only increase the dynamic pressure difference of the system, but also increase the power loss of the pressurized equipment. Big. After repeated calculations, it is concluded that the pipeline flow rate of the fire water supply system is 1.5m/s. Reasonable determination of the system pipe diameter and pipeline loss is one of the important measures to ensure the system is reasonable, water-saving and energy-saving.

　　5. Reasonably set the system maintenance separation valve to reduce the maintenance discharge water volume

　　 Reasonable setting of the separation valve for system maintenance can not only ensure that the system is shut down to a small limit, but also reduce the amount of water discharged from maintenance as much as possible. Especially in the indoor fire hydrant system, the risers are often connected in a ring shape. If the maintenance valve is not set properly, once the stainless steel flange pipe or the fire hydrant fails, the maintenance drainage volume will be large. This not only affects the use of systems and buildings, but also causes a waste of water resources. A reasonable approach is to set up maintenance control valves at the top and bottom of the fire riser pipe and the appropriate positions of the fire ring cross pipe.

　　6. ​​Set up a fire-fighting water pump inspection return system

　　 Due to the requirements of the system itself, the fire water pump is required to be equipped with a water discharge valve for inspection. During the inspection, it was found that most of the water discharged from the inspection discharge valve in the design was directly discharged to the pump house trench. In this way, when the water pump is inspected, the amount of water is wasted and the energy consumption of the pump room to improve drainage is increased. It is a reasonable water-saving and energy-saving measure to set up a water flow indicator device on the patrol water discharge pipe to directly lead the patrol water discharge valve back to the fire-fighting pool.

　　7. Transfer overflow water to the fire fighting pool in the middle of the fire fighting system

　　 Intermediate transfer water tanks are often installed in super high-rise buildings, and relay water tanks are often required in general high-rise building automatic sprinkler relay water supply facilities. In the usual design, the overflow water from the transfer water tank and the relay water tank is often directly discharged. If the transfer volume or adjustment volume of the transfer water tank or relay water tank is set improperly, the overflow water volume of its working state will be very large, which will inevitably cause water waste. Therefore, connecting the overflow water back to the fire-fighting pool can not only maximize the use of fire-fighting water to increase the fire intensity, but also reduce the loss of water to a minimum.

　　 8. Choose a reliable fire-fighting pool inlet control valve to reduce the overflow and drainage caused by the failure of the control valve

　　 The current fire-fighting pools are generally set up independently. Since the water level of the pool rarely changes, the water inlet control valve of the pool is in a non-operating state all year round. And because it is located at the interface between air and water, it is easy to malfunction due to rust and other reasons. The water inlet pipe of the pool is generally large. Once the water inlet control valve fails, a large amount of water will enter the fire pool and be discharged into the outdoor rainwater pipe network or the underground water pump house through the overflow water pipe of the pool. While causing a lot of water waste, it will also cause great damage to the control equipment of the pump house and the foundation of the main building.

　　Ensuring the fire water system is an important measure to ensure the city. However, there is no conflict between the system and the system's water saving. As my country is currently facing a serious shortage of water resources, it is necessary to implement water-saving measures in the water fire-fighting system. This requires us to establish awareness of fire protection and water conservation from top to bottom, and carry out a wide range of revolutionary optimization changes to the regulatory requirements and system design of the fire water system, so that it can meet the requirements of the city and save water and energy. In short, equal emphasis on saving water.

High-rise building fire-fighting water supply in parallel with stainless steel flange pipe network for water supply

　　 In actual work, generally according to the principle of "static pressure division, dynamic pressure check", the high-rise fire water supply system is divided into 50~60m or so, and the parallel fire water supply method is adopted. Among them, in order to ensure the two-way water supply condition of the fire hydrant standpipe, the fire hydrant system should be equipped with a ring network at the top and bottom of each subarea.

　　 1. Parallel water supply method

　　 Parallel water supply includes two modes: sub-pump and derivative multi-outlet pump water supply. The sub-pump water supply method means that each district has its own independent fire pump, roof water tank, and water pump adapter. This is a more traditional method. Its advantage is that it is more suitable for two kinds of commercial and residential buildings and comprehensive buildings with different functions, especially for buildings used by different property management units in the future and construction projects that are implemented in two phases and have large height differences. The disadvantages are: ①Because each area is independent, the pump room requires a larger area and the roof water tank occupies a larger area. If the middle water tank is installed in the building, it will also have an adverse effect on the indoor environment of the use floor, such as water stains on the partition wall and water inlet noise. ②As each area must be equipped with independent pump adapters, the number of pump adapters in the whole building is relatively large. ③When a fire occurs on the floor of the two compartments, the fire pumps in the two areas need to be activated at the same time, and the corresponding power supply load should be considered based on the power consumption of the two areas at the same time; if the fire pool is set up, the capacity should also be considered based on the water used in the two areas at the same time. In view of its main shortcomings, the high-level fire-fighting parallel water supply system can adopt the water supply mode of multi-outlet pumps. But when using this system, it should be noted that when the two outlets on the interface supply water at the same time, the head of the high and low zone will fluctuate, the high zone will exceed the head of the nameplate, and the low zone will be lower than the head of the nameplate; the higher the flow, the lower the zone. The smaller the flow, the closer the head in the high and low zone is to the equal value of the nameplate, so corresponding measures should be adopted in the design. In addition, the water from the roof water tank can be supplied to each partition through the pressure reducing valve to reduce the intermediate water tank. In summary, the water supply mode of multi-outlet pump is an ideal water supply scheme with economical and reliable system.

　　2, decompression water supply method

　　 Pressure-reduced water supply includes two ways of water supply by pressure-reducing valve and pressure-reducing water tank. The water supply mode of the pressure reducing valve refers to: a group of roof water tanks and fire pumps are used in multiple partitions, and water is supplied to each partition in parallel through the pressure reducing valve. Compared with the parallel water supply method, this system can save fire water pumps, roof water tanks and water pump adapters, which can also save a number of construction areas and vertical stainless steel flange pipes.

　　 Attention should be paid to the use of this water supply method: In order to ensure that the system is still in a normal state when the pressure reducing valve is repaired, there should be no less than 2 main water supply pipes. When the main water supply pipe is introduced into the zone ring network that needs to be decompressed, a pressure reducing valve should be installed. For the sprinkler system, because it is branch-shaped water supply, if there are 2 or more hydraulic alarm valves behind the pressure reducing valve, 2 parallel pressure reducing valves (one used and one prepared) should be installed on the water supply pipe.

　　 The proportional pressure reducing valve is suitable for use in a system with a building height of less than 100m and only needs to be divided into two zones due to its small size, easy installation, and no need for on-site debugging. Especially in cities where there are large fire trucks, the boosting head of a fire truck pump can reach 120m. When a proportional pressure reducing valve is used for water supply, a set of water pump adapters is sufficient. When the height of the partition exceeds the water supply capacity of a fire truck, the excess part of the partition should be independently equipped with a water pump adapter. Therefore, the entire fire water supply system becomes relatively complicated. This is because the pressure reducing valve is designed to reduce pressure in a fixed proportion. If a set of water pump adapters are used in multiple districts, even the low-zone water will be supplied at the pressure of the high-zone water supply. This can be solved by connecting several fire trucks in series at any time, which brings inconvenience to the fire-fighting in the low-zone area.