Available in sizes from 3 through 12", wafer check valves can be installed on the discharge side of pumps in applications such as water treatment systems to prevent backflow flooding that could damage pump systems. The wafer check valve conforms to ISO 5752 face-to-face dimensions and is installed by slip-fitting the valve between two mating flanges. The valve body automatically centers on the mating flanges once the stud pack is installed. A directional flow arrow indicates the upstream and downstream sides of the valve. Valves have a body, disc and stopper assembly machined from solid PVC plate stock, which has excellent chemical-resistance and mechanical properties.