Abstract: This invention concerns a butterfly valve having a resilient, adjustable seat for pivoting disc. The seat comprises an elastomeric seating attached to a clamping ring which slides along the walls of the first portion of the flow passage extending through the body. A plurality of actuators extend through the clamping ring and seat ring into an axial annular wall to initially compress the seat ring. The flow passage is configured so that the axial wall of the clamping ring is uniformly exposed to the fluid pressure in the first passage portion.

Abstract: This invention concerns a butterfly valve having a resilient, adjustable body seat for the pivoting disc. The seat comprises a T-shaped elastomeric ring which is confined at one end by the transverse wall of an annular groove in the valve body and that another end by a clamping ring which slides along the wall of the flow passage extending through the body. The clamping ring is forced against the seat ring by a plurality of individual screw actuators spaced around its circumference and therefore selected portions of the seat ring can be compressed as needed to produce a leak-free seal around the entire periphery of the pivoting disc. The T-shaped elastomeric ring is held in place solely by mechanical forces in order to permit removal, maintenance, and replacement thereof.