Solenoid valve having hard tube fluid channels in valve seat and

Abstract

A valve assembly has a unitary teflon valve housing with six peripheral facets. A recessed area on the surface of each facet forms a valve seat. Pairs of fluid channels formed in the housing each terminate at openings at a central, planar area of a corresponding valve seat. A pair of rigid tubes are disposed in the openings at each valve seat, each tube forming a fluid-tight seal with periphery of the corresponding opening. The tubes extend slightly beyond the surface of the housing by a predetermined clearance. A diaphragm made of a resilient material covers the valve seat. The periphery of the diaphragm is in fluid-tight sealing engagement with the periphery of the valve seat. A central portion of the diaphragm is coupled to a solenoid above the diaphragm. The solenoid moves the diaphragm central portion between a closed position toward the valve seat and an open position away from the valve seat. When in the closed position, the diaphragm central portion sealingly covers the extended ends of the tubes while the predetermined clearance is maintained between the diaphragm and the valve seat to prevent fluid-borne particles from being compressed therebetween. When in the open position, the diaphragm central portion uncovers the ends of the tubes to allow fluid to flow between the fluid channels.