Spence Strainers' cast iron, carbon steel and stainless steel flanged- and wafer-style silent check valves are suitable for use where silent operation and cost are major concerns. The valves can be mounted vertically or horizontally to prevent flow reversal while eliminating water hammer and system surges normally associated with the sudden stoppage of a reverse flow. They are available in sizes 2 in. through 16 in., for pressures to 500 PSIG at 150