1. Stop valve: mainly used to cut off or connect the medium flow
Gate valve
Rising stem
Working principle: There is a gate opening and closing part inside the valve body. The movement direction of the gate is perpendicular to the direction of the fluid. Because it can block water like a sluice, it is called a gate valve.
Scope of application: outlet pipe and suction pipe of fire pump; outlet pipe and suction pipe of pressure regulating pump; fire water supply network.
Supplementary explanation: The swing rod of the rising stem gate valve is exposed, and the opening and closing degree is more intuitive, but the swing rod is also corroded.
Non-rising stem
Working principle: Same as the rising stem gate valve
Scope of application: suction pipe of fire pump; fire water supply network
Supplementary explanation: Compared with the rising stem gate valve, the swing rod of the non-rising stem gate valve is not exposed, and the opening and closing degree is not intuitive, which is suitable for concealed projects
Butterfly valve
Working principle: The closing part (valve disc or butterfly plate) is a disc, which rotates around the valve axis to achieve opening and closing.
Scope of application: fire pump outlet pipe, water suction pipe; indoor overhead pipe.
Supplementary explanation: The applicability of butterfly valve is similar to that of gate valve, and some provisions require it to have self-locking function.
Exhaust valve
Working principle: When gas overflows in the system, the gas will go up along the pipe and eventually gather at the highest point of the system. The exhaust valve is generally installed at the highest point of the system. When the gas enters the exhaust valve cavity, it gathers at the upper part of the exhaust valve. As the gas in the valve increases, the pressure rises. When the gas pressure is greater than the system pressure, the gas will cause the water level in the cavity to drop, and the float will drop with the water level, opening the exhaust port; after the gas is exhausted, the water level rises, and the float also rises, closing the exhaust port.
Scope of application: automatic sprinkler fire extinguishing system; dry fire hydrant; dry fire riser.
Supplementary explanation: Dry system, pre-action system and dry fire hydrant system are equipped with quick exhaust valves, and corresponding electric valves are also provided.
Automatic drip valve
Working principle: An automatic drip valve is installed on the valve body on the system side of the deluge alarm valve (the dry alarm valve is installed on the alarm pipeline and diverted from the alarm pipeline through a tee). The water leaking from the water supply side to the system side is automatically discharged through the drip ball valve. The drip ball valve is automatically closed when extinguishing the fire.
Scope of application: dry, pre-action, deluge automatic sprinkler fire extinguishing system.
Supplementary explanation: It is similar to the exhaust valve, with the characteristics of opening and draining at low pressure and automatically closing at high pressure.
Low leakage and high sealing valve
Working principle: A valve set in the pipeline to prevent the system from malfunctioning due to the accumulation of driving gas leakage.
Scopeof application: gas fire extinguishing system.
Supplementary explanation: Installed on the system startup pipeline, it is in the open state under normal circumstances and is closed only when the inlet pressure reaches the set pressure. Its main function is to remove the gas accumulated in the startup pipeline due to gas source leakage.
2. Regulating valves: mainly used to regulate the pressure and flow of the medium
Pressure reducing valve
Proportional type
Working principle: The pressure reducing valve is a valve that reduces the inlet pressure to a certain required outlet pressure through regulation, and relies on the energy of the medium itself to automatically maintain a stable outlet pressure. The proportional type uses the pressure difference caused by the different cross-sectional areas of the piston at both ends of the valve body to change the pressure after the valve to achieve the purpose of reducing pressure.
Scope of application: overpressure at the fire hydrant outlet; water supply by pressure reducing valve; first stage of series pressure reduction.
Supplementary explanation: vertical installation is recommended.
Pilottype
Workig principle: the opening of the opening and closing parts in the control valve body is used to adjust the flow of the medium, reduce the pressure of the medium, and at the same time, the opening of the opening and closing parts is adjusted by the pressure after the valve, so that the pressure after the valve is kept within a certain applicable range.
Scope of application: overpressure at the fire hydrant outlet; water supply by pressure reducing valve exceeds 1.20MPa; second stage of series pressure reduction, the pressure difference before and after the valve should be ≤0.40Mpa.
Supplementary explanation: horizontal installation is recommended.
Throttle valve
Working principle: Throttle valve is a valve that controls fluid flow by changing the throttling section or throttling length.
Scope of application: fire hydrants, alarm valve groups.
Supplementary explanation: It is used to adjust the flow pressure, just understand it.
Three, check valve type: used to prevent medium backflow
Check valve
Working principle: The opening and closing parts are circular valve discs and rely on their own weight and medium pressure to produce a movement to block the backflow of the medium.
Scope of application: fire pump outlet pipe, high-level fire water tank outlet pipe, pressure-stabilizing pump outlet pipe, water pump connector and other locations.
Supplementary explanation: It includes silencer check valves and water hammer elimination check valves, which are set inside the valve body to reduce the sound of the valve disc hitting when the valve is closed and water hammer elimination measures.
Backflow preventer
Working principle: The backflow preventer is a valve device composed of two separated check valves and a safety drain valve.
Scope of application: Fire water pump outlet pipe that draws water from the municipal pipe network; District water supply series water pump outlet pipe; Outdoor fire hydrant water supply pipe; Fire water inlet pipe when it is supplied by the production and living water pipe network;
Supplementary explanation: It can be regarded as a reinforced check valve, the main function is to prevent water backflow. It can replace the check valve, but it cannot be replaced.
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