Abstract: A valve actuator for an automatic fluid control valve actuator which fits an Ames Company predetermined size valve housing and which is also suitable for use in a Cla-Val automatic fluid control valve housing of the same predetermined size and which valve actuator is interchangeable with the actuator of each respective manufacturer. The valve actuators range from 4 inches up to 12 inches and can be used as the original actuator of a set size within the range in either manufacturer's housing. The actuator includes a main body disposed on a shaft with a diaphragm and a diaphragm disk plate adjacent the main body on the shaft, all of which are retained by nuts threadedly engaged to the shaft.

Abstract: A check valve assembly, including a check valve and an associated check valve mounting flange. Additionally, a backflow preventer is shown, which uses a pair of check valve assemblies transversely positioned within a tubular housing. Also disclosed is a method for installing a downstream check valve to a mounting flange, located within a remote, outlet chamber of the backflow preventer housing. The check valve has an elongated base plate, generally elongated in shape. The mounting flange is provided with an elongated hole, sized and configured to pass a properly oriented downstream check valve during installation and removal procedures. The location and design of the downstream check valve assembly ensures that during backflow conditions, the check valve compresses against the mounting flange in sealing engagement.

Abstract: A differential loading fluid check valve, including a unitized valve body having a single service port in its sidewall for selective access to the interior chamber of the check valve. Check valve subassemblies are installed and removed through the service port for valve assembly and service. The same valve body can be configured for either single or double check valve operation by adding or removing check valve subassemblies. Each check valve subassembly includes a base with an aperture, a pivotally mounted clapper, and an overlying pivotally mounted cam arm, spring biased against the movable end of the clapper. An arcuate surface on the cam arm is engaged by the clapper as it moves from a closed position to an open position, providing a beneficial differential reduction in the pressure drop, or loading, through the check valve.