Exhaust gas control valve

Claim 1

An improved internal combustion engine exhaust gas control valve of the type in which a valve-closure member for controlling the flow of exhaust gas into the gas chamber located between an inlet port and outlet port is mechanically connected to a diaphragm by a valve stem, said diaphragm forming one wall of a vacuum chamber in fluid flow communication with an engine vacuum source and being biased to a position where said valve closure member closes said inlet port and in which an increase in engine vacuum causes said diaphragm to move against said bias for opening said inlet port, the improvement comprising a corrosion-resistant metal liner covering the inside walls of said exhaust gas chamber, inlet port, and outlet port that are exposed to said exhaust gas and also including a fluted flange mounted on and around said valve stem proximate said valve-closure member, the periphery of said flange flaring out from said valve stem and towards the walls of said gas chamber for protecting said stem from exposure to said gas and for forming a curved wall of said gas chamber when said valve-closure member is moved to open said inlet port, the exposed surfaces of said flange also being covered with a corrosion-resistant metal liner, said fluted flange providing rounded corners in said gas chamber for reducing locations at which condensate in said exhaust gas may accumulate.