In irrigation pipe networks, pressure reducing valves, pressure sustaining valves and pressure relief valves are three types of pressure control valves with different functions, which many users tend to confuse. Correctly understanding their differences is crucial for pipe network design.
Pressure Reducing Valve: It is used to reduce and stabilize downstream pressure. When the upstream pressure is high or fluctuates greatly, the pressure reducing valve automatically maintains the set outlet pressure through its internal regulating mechanism, protecting downstream drip irrigation and sprinkler irrigation equipment from high-pressure damage. It is suitable for mountain irrigation, long-distance water conveyance and multi-level pressure zoning systems.
Pressure Sustaining Valve: It is used to maintain the upstream pressure not lower than the set value. When the pressure in a certain section of the system is insufficient, the pressure sustaining valve automatically adjusts the opening to ensure that the section obtains stable water supply pressure. It is often used for stable pressure water supply of irrigation head filters and fertilization equipment to ensure the normal operation of the equipment.
Pressure Relief Valve: It is used for system overpressure protection. When the pipe network pressure exceeds the set safety value, the pressure relief valve automatically opens to release pressure, preventing water hammer and overpressure from damaging pipes and equipment. It is usually installed at positions prone to overpressure such as pump station outlets and downstream of filters.
The three types of valves have complementary functions, and reasonable configuration can effectively ensure the pressure stability and operation safety of the pipe network. When selecting models, the specifications shall be determined according to the system design pressure, flow rate and installation position, and attention shall be paid to matching the working pressure range with the system.