Patent ID: 7637284

Claim:
A sanitary diaphragm valve comprising: A flat lower plate having an upper side with a central recess area with a flat upper surface and a peripheral raised step surrounding the central recess area, said central recess area having a first round opening leading to a first tubular port on a lower side of the plate, and a second opening leading to a second tubular port on the lower side of the plate, each of said first and second round openings having a beveled edge recessed below the upper surface of said central recess area; A flexible resilient diaphragm lying on the lower plate and generally coextensive therewith so as to cover said central recess area and extend onto said peripheral raised step; A spacer having a predetermined thickness and extending above said peripheral step and coextensive therewith, the spacer lying atop said diaphragm; A flat upper plate coextensive with said lower plate and lying atop said spacer; the upper plate having a cylinder formed therein situated above said first opening and in register therewith, the cylinder extending upward above the second plate and having an open side facing said first opening; A piston within said cylinder and movable between a raised position allowing said diaphragm to move away from said first opening to permit fluid flow therethrough, and a lowered position in which the piston pushes the diaphragm against the recessed beveled edge of said first opening to close the first opening off to flow of fluid; Fastener means holding a peripheral edge of said plate and said spacer to the peripheral step portion of said lower plate, with the diaphragm being biased therebetween; and Means for controllably moving the piston to and/or from its lowered position to control movement of fluid through said first opening and said first tubular port.