Working Principle of Double Plate Check Valve

Wafer double plate check valve is also called butterfly check valve, which is commonly used in water supply and drainage systems.

The wafer check valve mainly depends on the flow of the medium itself to automatically open and close the valve plate to prevent the medium from flowing backward and the water from producing a hammer effect.
The two valve plates rotate around the middle valve shaft, like two sliding doors, and are equipped with springs to help the two valve plates move in the direction of valve closing.

The opening and closing process of the double-plate butterfly check valve is shown in the figure. Dual-disc construction employs two spring-loaded discs (half-discs), suspended from a central vertical hinge pin. When fluid flow begins, the disc opens under the resultant force (F) acting on the center of the sealing surface. The point of application of the reacting spring support force (Fs) is located outside the center of the disc face, causing the root of the disc to open first. This avoids the sealing surface friction phenomenon of the old conventional valve when the valve plate is opened, and eliminates the wear and tear of the components.

When the flow rate slows down, the torsion spring automatically reacts, making the valve plate close and close to the valve seat of the valve body, reducing the stroke distance and time of closing. When the fluid flows backwards, the valve plate gradually approaches the valve seat of the valve body, and the dynamic response of the valve is greatly accelerated, which reduces the influence of the water hammer phenomenon, thereby achieving non-impact performance.

When closing, the action point of the spring force makes the top of the valve plate close first, preventing the chafing phenomenon at the root of the valve disc, so that the valve can maintain the sealing integrity for a longer period of time.

Double plate check valve manufacturer

VALTECCN Valve is a manufacturer of high-quality check valves, providing high-quality wafer double-disc check valves, which can be designed with lugs, double flanges, and extended valve bodies.