Knife Gate & Slurry Valves

Knife gate valves isolate lines carrying slurries, solids, pulp and wastewater, where a sharp-edged gate cuts through the medium and seals against a seat that ordinary valves would clog. Seven Star LLC, an independent supplier in Muscat, supplies knife gate and slurry valves from Bray International to mining, cement, water treatment and process plants in Oman and the GCC.

Types of valve in this category

General-service knife gate valves have a wafer or lug body and a resilient or metal seat for wastewater, sludge and pulp. Unidirectional designs seal in one flow direction and are lighter and simpler; bidirectional valves seal in both directions for lines where flow can reverse. Slurry knife gate valves use elastomer sleeves or urethane liners so the gate passes between two seals and the abrasive medium never touches the body, which greatly increases service life in mineral tailings and ash handling. Bulk-solids and dry-powder versions isolate silos, hoppers and pneumatic conveying lines. Gates can be operated by handwheel, bevel gear, or pneumatic, hydraulic or electric actuators.

How to select a knife gate valve

Describe the medium first: solids content, particle size, abrasiveness and temperature. Then define size, pressure rating, flange drilling and whether sealing is needed in one or both directions. Choose the body material (ductile iron, carbon steel or stainless steel), gate material, seat or sleeve elastomer and the packing. For automated valves size the actuator for the gate thrust at maximum differential pressure.

Data needed for a quotation

Send the model, or size, pressure rating, flange standard, medium details, materials, operator and quantity.