Through Conduit Knife Gate Valve

through conduit knife gate valve (TC-KGV) is a specialized type of knife gate valve designed with a full-bore through-conduit port. When open, the valve provides an unobstructed flow path (no cavity or dead space), minimizing pressure drop and preventing solids or slurry from accumulating. It is mainly used in slurry, mining, pulp, wastewater, and bulk material handling industries, where conventional valves can clog or wear quickly.
through conduit knife gate valve is essentially a heavy-duty full-bore, zero-cavity knife gate valve designed for slurry and abrasive services, ensuring low-pressure drop and clog-free operation.

1.Structure of Through Conduit Knife Gate Valve

Body: Usually cast or fabricated steel, stainless steel, or alloy, with a straight-through bore.
Gate (knife plate): A flat, sharpened blade designed to cut through slurry, solids, or fiber-laden fluids.
Seats: Resilient (EPDM, NBR, PTFE, polyurethane) or metal-to-metal depending on service conditions.
Sealing: Elastomer or metal seats placed flush with the conduit to avoid pocket areas.
Stem: Rising or non-rising stem, operated manually (handwheel), electrically, pneumatically, or hydraulically.
Packing & Gland: Provide sealing around the gate to prevent leakage.
Through-Conduit Design: The gate retracts fully into the bonnet, leaving a full-bore unobstructed flow passage.

2.Standards (Reference) of Through Conduit Knife Gate Valve

Through conduit knife gate valves don’t have a single global standard, but they are often designed and tested according to:
MSS-SP-81: Knife Gate Valves (standard practice in U.S.)
API 6D / ISO 14313: For through-conduit designs in pipeline service (oil & gas)
ASME B16.5 / B16.47: Flange dimensions
EN 593 / ISO 5208: Leakage & pressure testing
NACE MR0175: For sour service (optional)

3.Features of Through Conduit Knife Gate Valve

Full bore through-conduit design: No cavity for slurry or solids to accumulate.
Low pressure drop: Straight-through flow path.
Self-cleaning action: Knife edge cuts through slurry/fibers and pushes solids out of the seat area.
Bi-directional shutoff (depending on design).
Available in large sizes (DN 50–2000+ mm).
Material flexibility: Carbon steel, stainless steel, duplex, special alloys.

4.Applications of Through Conduit Knife Gate Valve

Mining & mineral processing – slurry lines, tailings, concentrate transport.
Pulp & paper industry – pulp stock, wood chips, fiber suspensions.
Wastewater treatment – sludge, grit, raw sewage.
Power plants – fly ash, bottom ash slurry handling.
Bulk material handling – powders, pellets, cement, coal slurry.
Oil & gas pipelines (in some designs where API 6D through-conduit is required).

5.Operation of Through Conduit Knife Gate Valve

Open Position: Gate fully retracted into bonnet → flow path is completely unobstructed.
Closing: Gate lowers, knife edge cuts through medium, displacing solids, until tight shutoff on seat.
Actuation:
Manual: Handwheel or gearbox.
Pneumatic/Hydraulic: Cylinder-driven for quick/slurry service.
Electric actuator: Remote or automated control.
Safety: Ensure no pressure or slurry remains in the valve before servicing.

6.Maintenance Manual of Through Conduit Knife Gate Valve

Inspection:
Regularly check packing gland and adjust to prevent leakage.
Inspect seats and gate edges for wear.
Check actuator seals and connections.
Cleaning:
Flush valve with water or cleaning medium after handling slurry/abrasives.
Prevent buildup around the gate area.
Lubrication:
Lubricate stem threads and gearbox (if manual).
Avoid contaminating sealing surfaces.
Seat Replacement:
Remove gate and replace seat rings when wear or leakage is excessive.
Follow manufacturer’s torque instructions during reassembly.
Storage:
Store valve in dry conditions.
Keep gate slightly open to avoid sticking in storage.
Common Issues:
Gate jamming → caused by solid buildup → solved by flushing and cleaning.
Seat leakage → due to wear → replace seat.
Packing leakage → tighten gland or replace packing.