Abstract: An improved plug valve assembly having polymerically encapsulated seats and a machined inner surface is provided. The valve assembly comprises a valve body having an internal chamber, a plug disposed within the internal chamber and seat members supporting and sealing the plug. The seat members comprise a support frame which is completely encapsulated in a polymeric material. The process for encapsulating the seats includes providing a mold having, among other features, pins which position the support frame to provide for even application of the polymeric material to the support frame.

Abstract: An improved high performance butterfly is provided. The valve includes a valve body, a disk, an annular seat and a shaft. The disk has at least a portion of the circumference of the peripheral edge notched or beveled to provide better clearance of the annular seat and to reduce wear on the seat. The centerline of the shaft, corresponding to the center of rotation of the disk, is slightly offset from the centerline of the valve.

Abstract: An adjustable ball valve assembly having a vertically tapered chamber and an adjustment mechanism is provided. The adjustable ball valve includes a vertically tapered chamber, a ball disposed within said chamber, a valve stem connected to said ball, seat members, which include a rigid, solid support frame encapsulated in a polymeric material, supporting and sealing the ball and having a vertical taper corresponding to the chamber taper, locking members to prevent horizontal or rotational movement of the seat members and an adjustment mechanism for adjusting the seat members vertically within the chamber. The seat members are encapsulated by means of an injection molding process. The process includes providing an injection mold having, among other features, pins which position the support frame to provide for even application of the polymeric material to the support frame.