Knife Gate Valves

Knife gate valves cut through media that regular gate valves can't handle—fibrous pulp, settling slurries, tailings with suspended solids, sticky process residues that jam a parallel-seat gate before it reaches closed position. The blade-shaped gate slices through whatever sits in the flow path instead of trying to push it aside. That's the fundamental difference between a knife gate and a conventional wedge gate: one cuts, one wedges, and in media that accumulates on the seat surface, cutting wins. FLOWKS manufactures nine knife gate and slurry valve configurations—from lightweight wafer unidirectional isolation valves through heavy-duty long-pattern slurry valves, bidirectional dual-seat designs, polyurethane-lined abrasive service valves, and high-pressure units rated to Class 900. Wafer bodies fit between pipeline flanges with minimal footprint. Flanged bodies bolt directly into the line. One-piece ("whole unit") castings eliminate the body split gasket as a leak path. Bidirectional designs seat the gate from both directions with two independent sealing boundaries. Unidirectional designs seat in one direction only—cheaper, simpler, adequate for lines with known flow direction. Polyurethane lining shields every wetted surface from abrasive attack. High-pressure configurations use Stellite 6 metal seats and pressure seal bonnets for service beyond 50 bar. Every configuration shares the same operating principle: a sharp-edged gate that cuts through the media and seats against a peripheral seal, rather than wedging between two parallel faces that trap debris.

FLOWKS knife gate valves and slurry valves provide reliable shutoff in media conditions that defeat conventional gate valves—pulp stock, mining slurries, tailings transport, wastewater with suspended solids, and sticky process residues. The blade-shaped gate slices through accumulated media rather than wedging it aside, preventing seat cavity blockage and ensuring full-bore shutoff even after prolonged service in settling or fibrous media. Wafer knife gate valves offer the lightest, most compact isolation option for Class 150 service—unidirectional sealing, minimal installation footprint, lowest cost per size. Bidirectional knife gate valves add dual-seat sealing for lines with pressure on both sides of the valve. High pressure knife gate valves extend service to Class 300–900 with metal seats and pressure seal bonnets. Polyurethane-lined knife gate valves protect all wetted surfaces from abrasive slurries with full-body PU liners that outlast hard rubber by 5–10x. Heavy-duty long-pattern slurry valves provide structural depth and full-port bore for demanding mining and mineral processing applications. Whole unit slurry valves use one-piece cast bodies to eliminate the body gasket leak path entirely. High pressure slurry valves combine abrasive media resistance with Class 300–900 pressure ratings and Stellite 6 metal seats. Unidirectional sealing knife gate valves deliver cost-effective single-direction isolation for lines with consistent flow direction. Manual, pneumatic, and hydraulic actuation options available across all configurations.