Patent ID: 7059586

Claim:
A knife gate valve comprising: a valve body comprising mating halves that in an assembled configuration define a flow channel extending through the body, a knife gate adapted to slide within a gate channel between the halves of the valve body into an open position that allows flow within the flow channel and a closed position that blocks flow within the flow channel, a single gate seal mounted in a gate seal chamber defined by the mating valve body halves, the gate seal having a sealing surface lining the gate channel for creating a seal with a perimeter of the knife gate, and an integral gasket extending from the gate seal in a direction opposite the sealing surface and compressed between the body halves; and a chest seal mounted in a chest seal chamber defined by the mating valve body halves, the chest seal comprising a body member having a peripherally enclosed knife gate slot for receiving the knife gate, expandable sealing surfaces on upstream and downstream sides of the knife gate slot for creating a seal with the knife gate, and one or more injection chambers adapted to receive an injectable packing, each chamber having a cross-sectional area that is completely surrounded by the body member.