The difference between the safety valve and the pressur […]
The difference between the safety valve and the pressure reducing valve and its main role:
The safety valve is a special valve in which the opening and closing member is in a normally closed state under the action of an external force. When the pressure of the medium in the equipment or the pipeline rises above a prescribed value, the medium is prevented from exceeding the specified value by discharging the medium outside the system. . Safety valves are automatic valves, mainly used in boilers, pressure vessels and pipelines. The control pressure does not exceed the specified value, which plays an important role in protecting personal safety and equipment operation. Note The safety valve must be pressure tested before it can be used.
Safety valves provide safety protection in the system. When the system pressure exceeds the specified value, the safety valve is opened, and a part of the gas/fluid in the system is discharged into the atmosphere/pipe, so that the system pressure does not exceed the allowable value, thereby ensuring that the system does not cause an accident due to excessive pressure.
The pressure reducing valve is a valve that adjusts the inlet pressure to a certain required outlet pressure and relies on the energy of the medium itself to automatically maintain the outlet pressure. From the point of view of fluid mechanics, the pressure reducing valve is a throttling element whose local resistance can be changed, that is, by changing the throttling area, the flow velocity and the kinetic energy of the fluid are changed, resulting in different pressure losses, thereby achieving the purpose of decompression. Then, relying on the adjustment of the control and regulation system, the fluctuation of the post-valve pressure is balanced with the spring force, so that the post-valve pressure remains constant within a certain error range.
The working principle of the pressure reducing valve is to reduce the water pressure by the local resistance of the flow passage in the valve to the water flow. The range of the water pressure drop is automatically adjusted by the pressure difference between the inlet and outlet of the membrane or the piston connected to the valve flap. The principle of constant pressure reduction 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 ratio of the piston area on the inlet and outlet sides. The pressure reducing valve works smoothly and without vibration; there is no spring in the valve body, so there is no spring corrosion and metal fatigue failure; the sealing performance is good and does not leak, so the pressure is reduced (when the water flows) and the static pressure is reduced (the flow rate is 0 o'clock); especially during decompression without affecting water flow.