Swing check valves

The swing check valve consists of a double flanged body and bonnet which are manufactured from cast ductile iron. The upper part of the body, just under the bonnet, accommodates the valve disc when in the fully open position. The shaft is positioned above the top of the seat and is installed horizontally, supported at both ends by either plastic or metallic bushes. The shaft is free to rotate and usually one end protrudes from the body allowing the fitting of optional levers and weights. The disc is circular and is attached to the shaft via hinge arms. When closed, the disc seals onto the metal seat section within the body. The disc seal can be either resilient of metallic.

The operation of the swing check valve is based on a rotary motion. Under flow conditions, the fluid exerts a force on the disc which causes it to rotate upwards. When the flow reduces, due to gravity, the disc returns back to its closed position. Then the flow reverses, the pressure of the fluid acting on the disc forces it onto its seat which seals the valve and prevents flow reversal.

AVK swing check valves feature very easy access to maintenance and can be installed in both horisontal and vertical positions.

The main advantages of Swing check valve

The main advantages for swing check valves are that they can be designed with a full bore design. This results in very low head loss across the valve during full flow conditions. This design feature provides an unobstructed flow path which greatly reduces turbulence and also allows this valve type to be used for both water and waste water applications. These valves can also be designed with relatively low disc weights which reduces the force required to open and close the valve, thus are suitable for operation in both low and high pressure applications.