In fire fighting fittings protection systems and fluid systems, valves with various functions are installed. Some valves are responsible for opening and closing the fluid in the pipeline, some valves are responsible for regulating the flow of fluid in the pipeline, and some valves are used to regulate the pressure in the pipeline. 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.
From the perspective of fluid mechanics, the pressure reducing valve is a throttling element with variable local resistance, that is, by changing the throttling area, the flow rate and the kinetic energy of the fluid are changed, resulting in different pressure losses, thereby achieving the purpose of pressure reduction. Then, relying on the regulation of the control and regulation system, the fluctuation of the pressure behind the valve is balanced with the spring force, so that the pressure behind the valve remains constant within a certain error range.
Working Principle of the Pressure Reducing Valve
The fire protection pressure reducing valve relies on the local resistance of the flow channel in the valve to the water flow to reduce the water pressure. The range of the water pressure drop is automatically adjusted by the inlet and outlet water pressure difference on both sides of the film or piston connecting the valve disc. The fixed ratio pressure reduction principle is to use the water pressure ratio control of the floating piston in the valve body, and the pressure reduction ratio at the inlet and outlet ends is inversely proportional to the piston area ratio on the inlet and outlet sides. This type of pressure reducing valve works smoothly without vibration; there is no spring in the valve body, so there is no worry about spring rust and metal fatigue failure; the sealing performance is good and there is no leakage, so it reduces both dynamic pressure (when water flows) and static pressure (when the flow rate is 0); especially, it does not affect the water flow rate while reducing the pressure.
Working Principle of Pressure Reducing Valve
The pressure reducing valve uses the opening of the opening and closing parts in the control valve body to adjust the flow of the medium, reduce the pressure of the medium, and at the same time adjust the opening of the opening and closing parts with the help of the pressure behind the valve, so that the pressure behind the valve is kept within a certain range, and spray cooling water into the valve body or behind the valve to reduce the temperature of the medium. This valve is called a pressure reducing and temperature reducing valve. The pressure reducing valve is included in the automatic selection of quick and easy optimization. The characteristic of this valve is that it keeps the outlet pressure and temperature values within a certain range when the inlet pressure is constantly changing.
Advantages of Using A Pressure Reducing Valve in A Pipeline
Although there is a large head loss when water flows through the pressure reducing valve, it is still energy-saving overall because it reduces water waste and makes the system flow distribution reasonable, improves the system layout and working conditions. When the medium is steam, it is advisable to use a pilot piston pressure reducing valve or a pilot bellows pressure reducing valve. For the convenience of operation, adjustment and maintenance, the pressure reducing valve should generally be installed on the horizontal pipeline.
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