Dual Flap Check Valve

Dual Flap Check Valve

API standard dual flap check valves are designed to prevent backflow in pipelines and systems by using two flaps or discs that work in tandem. These valves are used in a variety of industrial applications where backflow prevention is crucial, and their design is particularly useful for managing larger flow volumes and high-pressure systems.

General Description

Function: Dual flap check valves are used to allow flow in one direction while preventing backflow in the opposite direction. They are designed to handle larger volumes of fluid and are often employed in high-pressure and high-flow applications.

Construction: The primary components of a dual flap check valve include:

Flaps (or Discs): Two hinged flaps or discs that open and close to allow or block the flow of fluid. These flaps are usually mounted on a central shaft and are designed to move in unison.

Body: The main structure of the valve that houses the flaps and other internal components. It is typically made from materials such as cast iron, carbon steel, stainless steel, or alloy steels.

Hinges: Components that allow the flaps to pivot open and closed. The hinges are designed to ensure smooth operation and minimal resistance.

Seat: Provides a sealing surface around the flaps to prevent leakage when the valve is closed. Seats can be made from materials like elastomers or metals, depending on the application.

API Standards

API 6D/594/603

  • Dual Flap Design: The use of two flaps allows for balanced and efficient flow management. The flaps open to allow flow in the forward direction and close to prevent backflow, providing a more reliable and stable operation compared to single flap designs.

    Materials:

    Body Materials: Cast iron, carbon steel, stainless steel, and alloys suited for the application.

    Flap Materials: Stainless steel, bronze, or other corrosion-resistant materials.

    Seat Materials: Elastomers like PTFE or EPDM, or metals for high-temperature and pressure applications.

    Pressure Rating: Dual flap check valves are available in various pressure ratings, such as ANSI Class 150, 300, 600, etc., to match different application requirements.

    Size Range: These valves come in a wide range of sizes to accommodate different pipeline diameters and flow rates.

    End Connections: Can be equipped with various end connections including flanged, threaded, or welded, depending on the installation and system requirements.

  • Oil and Gas, Water and Wastewater, Chemical Processing, Power Generation

  • Dual flap check valves operate automatically based on the direction of fluid flow. The flaps open when the fluid flows in the intended direction and close to prevent backflow. The dual flap design helps ensure balanced and reliable operation.