Knife Gate Valve -- Unidirectional Wafer Slurry WCB EPDM
Heavy-Duty Slurry Isolation Valve for Pulp, Mining, and Ash Handling
Document No.SV-DS-SPC-005
RevisionRev A
DateMay 2026
ManufacturerSupreme Valves India, Ahmedabad, Gujarat, India
This datasheet covers unidirectional wafer knife gate valves in WCB with EPDM sleeve for on/off isolation in pulp and paper stock, mining slurry, power plant ash, and wastewater grit applications.
Technical Specifications
| Parameter | Specification |
|---|
| Valve Size Range | DN50 to DN900 (2" to 36") |
| Pressure Rating | PN10 / PN16 / Class 150 |
| Body Material | WCB carbon steel, SS304, SS316, ductile iron GGG50 |
| Gate Material | SS304 or SS316 bevelled and polished to knife edge |
| Sleeve Material | EPDM, NBR, VITON, PTFE, or polyurethane |
| Temperature Range | -20°C to +120°C (EPDM), +200°C (VITON/PTFE) |
| End Connections | Wafer lug ISO 5752 / MSS SP-81 |
| Operation | Handwheel, chain-wheel, bevel gear, pneumatic or electric actuator |
| Gate Travel | Full bore unobstructed passage when open; gate fully retracts into bonnet |
| Options | Deflector cone, scraper, purge ports, limit switches |
Materials of Construction
| Component | Material |
|---|
| Body | WCB carbon steel or ductile iron, wafer profile with machined sealing faces |
| Gate | SS304 or SS316 plate, bevelled to knife edge, polished to Ra 1.6 µm on sealing faces |
| Sleeve / Seat | EPDM or polyurethane moulded sleeve, replaceable, captures gate on both sides |
| Packing | PTFE-impregnated braided fibre or graphite for high-temperature service |
| Yoke / Bonnet | WCB or SS304 open yoke with gate travel guides and position indicator |
| Stem | SS304 or SS316 with ACME threads, handwheel nut with thrust bearing |
| Hardware | SS304 studs and nuts; B7 studs for high-temperature service |
Testing & Inspection
| Test | Requirement |
|---|
| Test Standard | API 598 / MSS SP-81 shell and seat test |
| Certification | CE, ISO 9001 |
Applicable Standards
| Standard | Description |
|---|
| Design Standard | MSS SP-81 / API 600 (adapted) |
Notes
- Knife gate valves are designed for on/off isolation only; do not use for throttling service as gate and sleeve erode rapidly under partial opening.
- Unidirectional design has inlet and outlet marking; reverse flow will not seal and may damage sleeve; confirm flow direction at order.
- Deflector cone is strongly recommended for abrasive slurry >5% solids by weight; specify slurry composition and velocity at order.
- For vertical installation with downward flow, specify bottom purge port to prevent solids accumulation in bonnet cavity.
- Pneumatic actuator must include adjustable cushioning to prevent gate slam at end of stroke; EPDM sleeve damage occurs at >0.3 m/s gate speed.
