Abstract: A knife gate valve is provided, comprising: a unitary valve body having a flow channel extending there through, a guide segment and a stuffing box. A knife gate is located in the guide segment, the stuffing box and the flow channel and is slideable between an open and closed position. Lateral seals are provided in the stuffing box and can be replaced while the valve body is connected in its associated fluid system. These seals include an injectable sealing material contained in the stuffing box. A knife gate seat is provided in the valve body for sealing the knife gate and it can be replaced without completely removing the valve body from its associated fluid system.

Abstract: A knife gate valve is provided, comprising: a unitary valve body having a flow channel extending there through, a guide segment and a stuffing box. A knife gate is located in the guide segment, the stuffing box and the flow channel and is slideable between an open and closed position. Lateral seals are provided in the stuffing box and can be replaced while the valve body is connected in its associated fluid system. These seals include an injectable sealing material contained in the stuffing box. A knife gate seat is provided in the valve body for sealing the knife gate and it can be replaced without completely removing the valve body from its associated fluid system.

Abstract: A gate valve seal for a gate valve including a body having an inlet aperture and an outlet aperture, and a gate closure reciprocally disposed within the body between a closed valve position where the gate closure blocks the apertures and an open valve position where the gate closure does not block the apertures. The seal includes a first resilient seat for placement in the inlet aperture of the gate valve body and a second resilient seat for placement in the outlet aperture of the gate valve body. The seats sealingly engage one another and the gate closure when the closure cycles between the valve positions. Each of the seats includes an inner diametrical surface which generates sealing pressure that increases as internal pipeline pressure increases.