Ball valve seat ring construction

A spherical plug valve, comprising:

• a. a valve body having a valve chamber therein, flow passageways through said valve body in communication with said valve chamber, a spherical plug member positioned in said valve chamber movable between open and closed positions relative to said flow passageways and a lubricant passageway through said valve body for seat lubrication,
• b. an annular seat pocket in said valve body around at least one of said flow passageways and having a seat supporting abutment,
• c. a seat ring positioned in said seat pocket having inner and outer concentric seat members of generally cylindrical form arranged in juxtapositional relation to each other, and a seal ring mounted between said seat members and having an end portion in contact with the exterior surface of said spherical plug member, said outer seat member having an inside peripheral surface facing said inner concentric seat member, a seal ring mounting groove around said inside peripheral surface at one end portion thereof to receive and mount said seal ring, and said outer seat member having a lubricant groove around a mid-portion of the outer peripheral surface thereof, said inner seat member having an outer peripheral surface adjacent said outer seat member inside surface with one end of said outer peripheral surface overlying a mid-portion of the inner surface of said seal ring such that said inner seat member retains said seal ring in said seal ring mounting groove,
• d. said outer seat member having a plurality of circumferentially spaced apertures therearound which are radially disposed relative to the seat members and located in said peripheral lubricant groove, said inner seat member having a plurality of circumferentially spaced apertures therethrough aligned with said apertures through said outer seat member, a plurality of fasteners extending through said apertures in said seat members to secure said seat members together, said outer seat member having a greater number of said circumferentially spaced apertures therethrough than said inner seat member,
• e. a lubricant passageway between said seat members connecting said outer seat member circumferentially spaced apertures and said seal ring and including an annular space between said outer seat member inside peripheral surface and the outer peripheral surface of said inner concentric seat member, said annular space extending between said outer seat member circumferentially spaced apertures to said seal ring, said lubricant passageway including a plurality of circumferentially spaced recesses aligned with said flow passageways and located in the outer peripheral surface of said lubricant groove to said seal ring inner surface,
• f. cooperating means on said inner seat member and said outer seat member to longitudinally position said seat members such that said circumferentially spaced apertures of both said seat members are aligned to facilitate mounting said fasteners,
• g. said seat members each having an outer end which is opposite to said seal ring and oriented generally transverse to the longitudinal axis of said flow passageways, and
• h. resilient means in said seat pocket contacting the outer ends of said seat members to urge said seat ring toward and into fluid-tight sealing contact with said spherical plug member.