Patent ID: 8205860

Claim:
A valve possessing a structure in sealing surfaces ( 21 ) of seat rings ( 14 ) used for mitigating abrasive wear or galling between it and surface of closure member ( 17 ) in their relative sliding contact during its on-off or regulating movement, said valve comprising of: a. a body housing, said body housing having an upstream passageway and a downstream passageway and an inner chamber therebetween for disposing the closure member ( 17 ) has a pair of annular recesses composed of a shoulder and an interior circumferential surface encircling said passageways and being close to the inner chamber for accommodating the seat rings ( 14 ) respectively; b. the closure member ( 17 ), said closure member ( 17 ) being disposed in said inner chamber, and its exterior surface keeping relative sliding contact with part or all of the sealing surface ( 21 ) of the seat rings ( 14 ); and c. two seat rings ( 14 ), said seat rings ( 14 ) are positioned within said annular recesses in the passageways of said body housing, and are clamped between said body housing and said closure member ( 17 ) respectively, the sealing surface ( 21 ) of each of said seat rings ( 14 ) is in a sliding contact with the exterior surface of said closure member ( 17 ) for shutting off the fluid flowing in said body housing when the valve is closed, and has an opposite end face abutted on the shoulder in said annular recesses; and a bore of said seat rings ( 14 ) encircles the passageways respectively; wherein two annular grooves ( 27 ) around the bore of said seat rings ( 14 ) are arranged in sealing surface ( 21 ) of said seat rings ( 14 ) and filled with lubricant or grease used for oiling repeatedly said sealing surface ( 21 ) and the exterior surface of said closure member ( 17 ) to create an additional coating on both of the surfaces; two partitions ( 30 ) for dividing each of annular grooves ( 27 ) into two separate grooves ( 31 ) and ( 32 ) are respectively inserted into each piece of grooves ( 29 ) in areas defined by two segments (ab) and (bc), as well as two segments (a′b′) and (b′c′) on the sealing surface ( 21 ) of said seat rings ( 14 ), in which the segments ab and a′b′ are projecting lines of a line ( 28 ) passing through centre of the seat rings ( 14 ) onto the sealing surface ( 21 ), the segments bc and b′c′ are projecting lines of two lines ( 22 ) being vertical to the line ( 28 ) and tangentially past inner edge ( 14 a ) of sealing surface ( 21 ) of seat rings ( 14 ) onto the sealing surface ( 21 ), both bc and b′c′ are on the same side of the line ( 28 ).