【2025 Fun Fact】The differences between pressure relief valves, safety valves, pressure stabilizing valves, and pressure discharge valves

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This post was last edited by zhoudingshengs on 2025-1-17 08:54. Differences between pressure reducing valves, safety valves, pressure stabilizing valves, and pressure relief valves: 1. Pressure reducing valve – A pressure reducing valve is a valve that reduces the inlet pressure to a desired outlet pressure through regulation, and relies on the energy of the medium itself to keep the outlet pressure stable automatically. From a fluid dynamics perspective, a pressure reducing valve is a throttling element whose local resistance can be varied; by changing the throttling area, the flow velocity and the kinetic energy of the fluid are altered, resulting in different pressure losses and thus achieving the purpose of pressure reduction. Then, through the regulation of the control and adjustment system, the fluctuations in pressure behind the valve are balanced with the spring force, allowing the pressure there to remain constant within a certain error range. (1) Used to reduce high-pressure fluid to the desired low-pressure level to meet the system’s requirements. (2) It is capable of stabilizing the output pressure and ensuring that the system maintains a constant pressure under any flow rate. (3) Usually installed on high-pressure pipelines. 2. Safety valve: A safety valve is a special type of valve in which the closing element remains in a closed position under external forces. When the pressure of the medium inside the equipment or pipeline rises above the specified value, this valve releases the medium outside the system, thereby preventing the pressure from exceeding that specified level. Safety valves belong to the category of automatic valves and are primarily used in boilers, pressure vessels, and pipelines to ensure that pressure does not exceed specified levels, thereby playing a vital role in protecting both human safety and the proper operation of equipment. (1) Devices used to protect equipment and systems from damage caused by excessive pressure. (2) When the system pressure exceeds the preset safety value, it will open automatically to release the excess pressure. (3) It is usually installed upstream of critical equipment or systems. 3. Pressure regulator: A pressure regulator is a device that maintains the pressure of the medium in a certain range within a specific area. Difference from a pressure reducing valve: A pressure reducing valve maintains the outlet pressure at a set value, regardless of how the inlet pressure changes, thereby serving to reduce pressure. Pressure regulator: Maintains a constant upstream pressure regardless of changes in downstream pressure and demand. (1) A device used to maintain system pressure stability. (2) Operate under pressure fluctuations by adjusting the fluid flow to maintain a constant pressure. (3) It is typically used in applications that require high-precision pressure control. 4. Pressure relief valve: When the pressure inside a device or pipeline exceeds the set pressure of the pressure relief valve, it opens automatically to release pressure, ensuring that the pressure of the medium within the device or pipeline remains below the set level. This helps to protect the device and pipeline from accidents. Pressure relief valves are primarily used in situations where pressure is too high; when the pressure exceeds the set value, the internal component of the valve is pushed open to release pressure promptly. Once the pressure drops, it returns to its original position. They are not very different from safety valves. Pressure relief valves are usually used for liquids, while safety valves are more often used for gases and steam.