





I. Key Structural Features
- Function Integration : Combining both "safety relief" and "pressure-holding/stabilization" functions, it automatically releases pressure when the system exceeds the set threshold and remains closed when the pressure drops below the holding level, fully complying with the functional requirements of GB/T 12243, "Spring-Loaded Direct-Acting Safety Valves."
- Sealed structure : Adopting Flexible Rubber Diaphragm Seal , featuring no metal-to-metal hard sealing wear issues, with leakage levels meeting the Class A standard specified in GB/T 13927 "Pressure Testing of Industrial Valves," ensuring high sealing reliability;
- Drive Method : By directly applying system medium pressure to the diaphragm, no external power source is required—this is a "self-actuated" control system with a response time of ≤1 second, making it ideal for unattended operational scenarios.
- Connection Type :The valve body features a flanged connection, with flange dimensions and sealing surfaces complying with the requirements of GB/T 9113 "Integral Steel Pipe Flanges," ensuring versatile installation compatibility.
- Adjustment mechanism : Built-in adjustable spring assembly allows for precise setting of the relief pressure and holding pressure range, with an adjustment accuracy of ±3%, meeting the national standard requirements for control precision in safety valves.
II. Main Technical Parameters (National Standard)
III. Main Component Materials (National Standard)
4. Dimensional Specifications (National Standard)
5. Typical Application Scenarios
- Urban Water Supply System : The water plant's clear water tank and pipeline pressurization pump station are used to stabilize system pressure, preventing overpressure that could damage pipes and equipment.
- Petrochemical industry : Pressure vessels such as storage tanks and reactors are equipped with safety relief devices at their outlets to ensure the safe operation of the equipment;
- Thermal Network Engineering : Hot water/steam network branch lines maintain stable system pressure, preventing pressure fluctuations that could compromise heating efficiency;
- Water Treatment Industry : Reverse osmosis equipment and ultrafiltration systems prevent membrane components from being damaged due to sudden pressure surges, while maintaining stable system operating pressure;
- Industrial Circulation System : Cooling circulating water and hydraulic systems, providing dual protection—overpressure relief for safety and constant-pressure maintenance under normal conditions.
6. Product Overview
Keyword






AX742X Diaphragm-Type Safety Relief and Pressure Maintaining Valve
The AX742X diaphragm-type safety relief and pressure-holding valve is a self-operated control valve that meets national standard requirements. It integrates both relief and pressure-holding functions, featuring a flexible diaphragm seal that achieves Class A leakage standards. Importantly, it responds swiftly to pressure changes without the need for external power. With flanged connections designed to fit industrial pipelines, this valve offers high adjustment precision and is compatible with various media, including water and oil products. Widely used in sectors such as water supply, chemical processing, and heating systems, it provides reliable protection for system pressure safety and stable operation—balancing both safety and cost-effectiveness.
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