Patent ID: 8601634

Claim:
A universal pig valve mechanism, comprising: a valve body defining a valve chamber and having a pig access opening in communication with said valve chamber, said valve body defining a longitudinal axis and having opposed axial ends; valve mounting members extending from said axial ends of said valve body for mounting said universal pig valve mechanism in a pipe line, each valve mounting member having a flow passage in communication with said valve chamber; a seat retainer member being mounted within an axial end of said valve body and defining an annular seat recess having an internal substantially cylindrical seat recess surface of defined diameter and having a lateral seat recess surface oriented in transverse relation with said internal substantially cylindrical seat recess surface and with said longitudinal axis; a closure member being removably mounted to said valve body and normally closing said pig access opening, said closure member being removable for pig insertion and removal; a valve ball member being mounted for rotation within said valve chamber and defining a substantially spherical external sealing surface and having a valve ball flow passage permitting a pig member to be inserted therein, said valve ball member being rotatable within said valve chamber to a flow position permitting fluid flow through said valve ball flow passage and a pig loading and retrieving position permitting movement of a pig member into and from said valve ball flow passage; a seat support member being sealed to said internal substantially cylindrical seat recess surface and being linearly moveable within said seat recess, said seat support member defining an annular planar seat support surface facing said valve ball member and being oriented in transverse relationship with said longitudinal axis; and a seat ring member being moveable within said seat recess and having an outer periphery of less diameter than said defined diameter, said outer periphery having external clearance with said internal substantially cylindrical seat recess surface, said seat ring member being moveable linearly by force transmitted thereto by said seat support member and being moved laterally within said seat recess by force received from said valve ball member upon lateral movement of said valve ball member, and providing said seat ring member with a self-centering and sealing relationship with said substantially spherical external sealing surface of said valve ball member.