Patent ID: 7350766

Claim:
A knife gate valve comprising: a valve body comprising mating halves each comprising an orifice, the orifices in an assembled configuration of the mating halves defining a flow channel extending through the body and a sealing chamber that extends in a first direction normal to the flow channel; a knife gate positioned to slide within a gate channel between the halves of the valve body between (a) a closed position in which the knife gate blocks flow through the flow channel and (b) one or more open positions in which the knife gate has been at least partially retracted in the first direction so that it permits flow through the flow channel; an elastomeric transverse seal mounted in the sealing chamber, the transverse seal comprising a body member having a peripherally enclosed knife gate slot for receiving the knife gate; a elastomeric perimeter seal comprising an inner surface and an outer surface, the inner surface comprising a sealing surface that lines the gate channel for creating a peripheral seal with the knife gate; and a pair of discrete elastomer liners, each liner positioned between the knife gate and one of the mating valve body halves and defining a chamber for receiving the perimeter seal, each liner having a port that corresponds to the flow channel and a sealing portion that extends into the sealing chamber to cooperate with the transverse seal, each liner having an inner face and an outward face comprising an orifice liner extension that lines the orifice of the corresponding valve body half, wherein the discrete elastomer liners are unattached to the perimeter seal.