Fire water system commonly used materials and equipment knowledge

Fire Water System Engineering Common Pipe Fittings

First, the type of fire water supply pipe

1. Ductile Iron Pipe: It is applicable to the buried pipeline in front of the alarm valve of the automatic sprinkler system and the buried pipeline of the hydrant system.

2. Welded steel pipe: Suitable for buried and overhead pipelines for fire hydrant systems and buried and overhead pipelines in front of alarm systems for automatic sprinkler systems and water spray systems for the delivery of low pressure fluids. According to the wall thickness can be divided into ordinary steel pipe and thicker steel pipe. According to different processes can be divided into ordinary welded steel pipe and hot dip galvanized welded steel pipe.

3. Seamless steel pipe: Suitable for the main pipe or the lower part of the system where the working pressure is higher. According to different processes can be divided into hot and cold rolling two.

Second, the selection of fire water supply pipe

1. Outdoor hydrant water supply system

( 1 ) When the outdoor fire protection is a life and fire combined pipeline system or a low-pressure firefighting water supply system, ductile iron pipes, welded steel pipes, hot-dip galvanized welded steel pipes with inner and outer walls, and PE water supply pipes , which allow lower pressure of the socket branch pipe, may be used. .

( 2 ) When the outdoor fire-fighting water supply system is a temporary high-pressure or constant-pressure high-pressure water supply system and the working pressure of the system is low, the above-mentioned pipe ( 1 ) may be used within the allowable pressure range of the pipe; when the working pressure of the system is high, Flanged ductile iron pipes, welded steel pipes, hot-dip galvanized ordinary steel pipes or thickened steel pipes, and seamless steel pipes shall be used according to the working pressure of the system.

2. Indoor hydrant water supply system

( 1 ) When the working pressure of the indoor fire hydrant system is ≤ 1.0Mpa , ordinary welded steel pipes and common hot-dip galvanized inner and outer welded steel pipes may be used.

( 2 ) When the working pressure of the indoor fire hydrant system is 1.0~1.6Mpa , the thick welded steel pipe, hot-dip galvanized welded steel pipe and seamless steel pipe can be used.

3. Automatic sprinkler system

The water distribution pipelines shall be made of hot-dip galvanized steel pipes inside and outside the wall. When the pipelines before the entrance of the alarm valve adopt the steel pipes with no anti-corrosion on the inner walls, filters shall be installed at the ends of the pipelines.

Third, the fire water supply pipe connection

1. Fire water supply commonly used pipe connection

2. General requirements for the connection of commonly used fire-fighting water pipes

( 1 ) When using hot dip galvanized steel pipes for inner and outer walls of fire hydrant water supply system piping, welding should not be used. When the inner wall of the system pipeline is not anti-corrosion pipeline, it can be welded, but the pipeline welding should meet the relevant requirements. After the automatic sprinkler system alarm valve can not be used for welding, threaded, grooved pipe joints or flanged joints should be used.

( 2 ) Hydrated water supply system Hot-dip galvanized steel pipe with a diameter greater than 100mm shall be flanged or grooved. Automatic sprinkler system pipe diameter greater than 100mm does not require the use of threaded connections, but requires a flanged connection or grooved connection point at a certain distance in the pipe diameter ≥ 100mm .

( 3 ) The fire hydrant system and automatic sprinkler system piping shall be threaded flanges when using flange connections, and secondary zinc plating when welding flanges are used.

( 4 ) When any pipe section needs to change the pipe diameter, reducer fittings and fittings that meet the standards should be used.

( 5 ) The relevant provisions of the "National Civil Construction Engineering Design and Technical Measures - Water Supply and Drainage" can be found in connection with fire protection pipeline connection methods and related technical requirements .

Fire water system engineering commonly used equipment

First, the fire water supply system

1. hydrant

The indoor fire hydrant is a ball-type valve faucet with an internally-connected coupling, which has a single outlet and a double outlet. Under normal circumstances, it is recommended to export the fire hydrant. There are two kinds of fire hydrant DN50 and DN65 , the former is used for 2.5 ~ 5L/s, the latter is used for each gun minimum flow is greater than or equal to 5L /s . The inlet end is connected to the fire riser and the outlet end is connected to the hose. High-rise building indoor fire hydrant caliber should choose DN65 .

2. Water gun

Water guns are one of the main tools for fire extinguishing. They are made of steel, aluminum alloys or plastics. Their function is to shrink the water flow and produce a full column of water to fight the flame. Indoor use of water-type water guns are commonly used. There are three kinds of commonly used nozzle diameters: 13 , 16 , and 19mm . The other end is provided with an interface connecting with the hose. The caliber is 50mm and 65mm .

Nozzle diameter of 13mm gun with a 50mm interface with the water with the DN50; nozzle diameter of 16mm gun is equipped with an interface 50mm or 65mm, and can be equipped with DN50 and DN65 hose; nozzle diameter gun 19mm feature of 65mm Interface, can be equipped with DN65 hose. High-rise building indoor fire hydrant water supply system, water gun nozzle diameter of not less than 19mm .

3. Hose

The water dragon has three types of hemp, cotton and rubber lining, and the pressure loss of the lining rubber is small, but the anti-folding performance is not as good as the hemp and cotton woven. There are two types of fire hoses commonly used indoors: DN50 and DN65 . The length of the fire hose is 15m , 20m , and 25m . It should not exceed 25m . Both ends of the hose are connected to a water gun and a fire hydrant.

The connection between the fire hydrants, the hoses and the water guns generally adopts an inner button type quick connector. In the same building, water guns, water hoses and fire hydrants of the same specifications should be used, which has facilitated maintenance, management and stringing.

4. Fire hydrant box

Fire hydrant boxes are used to place fire hydrants, water hoses, and water guns. They are usually concealed in the wall and can also be mounted and semi-dark. Its mounting height is based on the center of the fire hydrant bolts at a distance of 1.1m from the ground .

The size of the commonly used fire hydrant box is 800 × 650 × 200 ( 320 ) mm . It is made of wood, aluminum alloy or steel plate. The exterior door is open and the door should have obvious signs. The hose and gun must be placed neatly in the box.

5. Water pump coupling

The water pump coupling is an interface where the fire truck draws water from an outdoor water source or a municipal water supply pipe to the indoor fire pipe network. For more than four floors of factory buildings and warehouses, high-rise industrial buildings, houses with fire pipe networks, and other civil buildings with more than five floors, the indoor fire pipe network should be equipped with pump adapters.

The water pump combiner should be located outdoors to facilitate the access, use, and transportation of the fire engine. In addition to wall-type water pump couplings, there should be a certain distance from the external wall of the building, generally not less than 5m . Within the range of 15 to 40m around the pump adapter , there shall be an outdoor fire hydrant or fire-fighting basin for the fire truck to take water.

6. Fire Hose

Fire hoses are used when the person saves himself to extinguish the initial fire and reduce water damage caused by the fire extinguishing process. According to its setting conditions, it can be divided into self-rescue small-diameter fire hydrants and fire hose reels.

Second, the main equipment of automatic sprinkler system

1. closed nozzle

The automatic sprinkler is a key component of a closed automatic sprinkler system that sprays water through the action of a thermally sensitive release mechanism. It consists of a water outlet, a temperature sensing release (controller), and a splash tray. The shapes and styles are many. The following figure shows the commonly used low-melting-point metal controller automatic sprinkler and explosive bottle automatic sprinkler.

2. Open nozzle

The size, type, and thread and shape of the open nozzle are the same as those of the glass ball closed nozzle. It is made by removing the temperature sensing element and the sealing surface on the closed nozzle of the glass ball. It is usually used in the rain system, also known as the rain system. Open rain sprinkler.

3. alarm valve

The role of the alarm valve is to open and close the flow of the pipe network, pass the control signal to the control system and start the water alarm directly.

4. Flow indicator

Water flow indicators are used in wet sprinkler systems. When a sprinkler opens water or water leaks in the pipe network, the water in the pipe will flow, causing the blade in the water flow indicator to move with the water flow. After the delay circuit is connected for 20s to 30s , the relay will make contact with the electricity and send out the area. The electrical current signal is sent to the fire control room. The water flow indicator is usually installed on the water distribution pipe or branch pipe on each floor.

5. Delay device

The retarder is a tank container that is installed between the alarm valve and a hydraulic bell (or pressure switch). Used to prevent false alarms caused by the opening of the alarm valve due to water pressure fluctuations. After the alarm valve is turned on, the water flow will need to be filled with the retarder for about 30 seconds before being flushed with the water alarm.

The information in this article comes from the Internet and was reorganized and edited by China Rescue Equipment Network.