Check valve with conforming seat

A valve, comprising:

• a valve body including a first fluid port opening from the valve body, a second fluid port opening from the valve body, and an interior passage fluidly connecting the first fluid port and the second fluid port;
• a bore extending inwardly of a first wall of the valve body and having an annular first seat securement surface extending around an interior passage intermediate of the first fluid port and the second fluid port, the second fluid port fluidly connected to the bore;
• a cage disposed in the bore, the cage having an annular second seat securement surface having an inner circumferential surface having a first diameter defining the outer wall of a cage bore extending inwardly of the bore from the annular second seat securement surface and an opposed first annular surface, the annular second seat securement surface facing the annular first seat securement surface;
• a cover extending over the first wall of the valve body and the opening of the bore thereof, the cover including a cage engagement surface contacting the first annular surface;
• and
• an annular seat having a main body having an opening therethrough and a first annular seat surface facing and contacting the annular first seat securement surface of the valve body and a second annular seat surface, facing away from the first annular seat surface, the second annular seat surface comprising a first annular region having a flat annular sealing surface at a first elevation and extending radially inwardly of the first diameter of the inner circumferential surface of the annular second seat securement surface of the cage and a second annular region different than the first annular region and disposed about the first annular region, and the second annular region comprises at least one projection projecting from the annular seat to an elevation greater than the first elevation and contacting the annular second seat securement surface, the at least one projection extending circumferentially around the opening in the annular seat and including a first portion having a second elevation and a second portion having a third elevation different than the second elevation, and the first portion is circumferentially aligned with the second portion;
• and a seal sleeve reciprocally received within the cage, the sealing sleeve terminating, at a first end thereof, in an annular sleeve sealing surface, the annular sealing surface selectively engageable with the first annular region of the second annular seat surface and not engageable with the second annular region of the second annular seat surface.