A low-pressure, low-RPM 3-cylinder diaphragm pump, the Hypro 9915-DP1003 is a go-to choice for "soft wash" car wash needs, low-pressure cleaning services, and a number of other chemical applications. Chemical-resistant polypropylene over molded aluminum heads and manifolds make it both durable and easy to maintain. Three Duramax diaphragms, crown shaped pistons, aluminum case material.316 stainless steel spherical profiled valve poppet valves. Specifications: