The double disc check valve is a critical device in fluid piping systems, designed to prevent medium backflow while minimizing flow resistance through its unique dual-disc linkage structure. Inside the valve body, two symmetric discs are connected via hinges or springs. During forward flow, fluid pressure pushes the discs open, creating an unobstructed passage; when backflow occurs, the discs close simultaneously under the combined action of fluid pressure and gravity, effectively blocking reverse flow.
Core Structural Advantages
- Low Flow Resistance Design: When open, the discs align parallel to the fluid flow, forming a near-straight passage. This reduces pressure loss by over 40% compared to traditional check valves, making it ideal for large-diameter applications in water supply and drainage, as well as natural gas transmission.
- Rapid Closure Feature: The dual-disc linkage minimizes swing inertia, achieving a closure time of less than 0.5 seconds. This effectively prevents water hammer effects, safeguarding the integrity of the piping system.
- Vibration and Noise Reduction: Damping devices and elastic seals on the discs mitigate impact during opening and closing, maintaining noise levels ≤85dB—compliant with urban pipeline silence requirements.
Technical Classification and Materials
Connection Types:
- Wafer Type: Installed between two flanges, compact and suitable for pipes with diameters ranging from DN50 to DN600.
- Lug Type: The valve body features mounting lugs for easy positioning and fixation, ideal for frequently disassembled applications.
- Welded Type: The valve body is directly welded to the pipeline, ensuring high sealing performance, and is suitable for high-pressure systems (PN16-PN100).
Common Material Combinations: