Knife gate valve 101 – unidirectional

Available configurations

• Size range: DN 50–1400, subject to the selected configuration;
• Connections: wafer or lug, with PN10 or PN16 flange drilling;
• Sealing direction: unidirectional;
• Operation: handwheel, gearbox, pneumatic or electric actuator;
• Stem: rising or non-rising, depending on the configuration.

Seat and service options

• Soft seat: elastomeric sealing for tight shut-off;
• Reinforced soft seat: a retaining ring helps protect the seat and remove material adhering to the gate;
• Metal-to-metal seat: available where an elastomeric seat is unsuitable; a different leakage class applies;
• Inlet deflector: optional protection against direct wear from solids;
• Bottom flushing connection: optional means of removing accumulated material from the lower body cavity.

Process media

Water, condensate and other industrial liquids, including media with limited suspended solids. The catalogue describes liquid service with up to 5% suspended solids. Suitability for steam, petroleum products, chemicals or gases depends on the selected body, gate, seat and packing materials, as well as pressure and temperature. More demanding abrasive duty requires a separate selection review.

Material options

Duplex 2205 and Super Duplex 2507 can be specified for selected configurations. The combination of body, gate and seat materials is confirmed for the ordered valve.

Maximum shut-off differential pressure

Higher pressure ratings can be evaluated for custom-designed versions on request.

Sealing and temperature

Soft-seated variants are specified for leakage Class A according to ISO 5208. The catalogued metal-to-metal seat variants have leakage Class D. The series temperature range is −60°C to +300°C; the permissible range of an individual valve depends on its materials and seat design.