DeZURIK KSV Severe Service Knife Gate Valve

High-pressure knife gate valve for abrasive slurry isolation

The DeZURIK KSV is a severe service knife gate valve designed for high pressures and abrasive slurries in mining, including oil sands, steel, power, chemical, municipal sludge, biofuels and paper plants. Its rigid one-piece body, specifiable port diameter, hard-faced gate and rotatable seat rings make it an isolation valve for high-density, high-pressure slurry lines.

The bulletin states that all KSV valves give bi-directional drip-tight shutoff and meet MSS SP-135 for high-pressure knife gate valves. A Class 300 manual KSV is shown handling coarse tailings at 350 psi with velocities of 13 to 14 ft per second.

KSV technical specification

What sets the KSV design apart

The valve has a dual wear ring design: the hardened seat rings are identical, so they can be interchanged, rotated three times through four positions or replaced in the field. The beveled, knife-like gate edge cuts through solids, and gates are available with a hardened nickel-based non-stick overlay and tungsten bevel.

Purge ports in the chest let the interior be flushed, and lifting lugs are cast into the packing chamber. Dead-end design holds full rated pressure with the downstream side open to atmosphere. The full-force lockout system holds the full actuator force plus a safety factor on manual or powered actuators. A short body version matches MSS SP-135 face-to-face lengths for rubber-lined piping.

The raised-face body has drilled and tapped flanges, so the valve can be bolted between pipe flanges without a mating flange on one side. Mechanically retained resilient seats are offered in several elastomers and give drip-tight shutoff in both directions; metal-seated valves conform to the MSS SP-135 leakage requirement instead. Where high velocity wears the seat, chrome or tungsten carbide overlays of 6 mm or 13 mm can be specified on the seat rings.

Gate, packing and trim materials

The packing system is live loaded through a resilient O-ring, so compression is retained as packing wears, and the machined chamber with adjustable gland fully supports the gate. A rounded gate edge protects the packing. Mechanically retained seats avoid the cavities where solids pack, and the 360 degree gate guiding keeps the gate aligned over the whole stroke.

Ordering and accessories

The printed example is KSV,6,F1,CS,GLCW,CSHC-CS-TW13,CR*MNB-HD12-CS, built from style, size, end connection, body, packing, gate and seat ring, and resilient seat. The ASME class and port inside diameter are specified to match pipe; Class 150 ports can match any pipe ID and Class 300 ports match extra-strong pipe per ASME B36.10.

Options include bonnets, gate guards, a double block and bleed design (KSV-DBB), solenoids, switches and positioners. Always confirm slurry density, particle size and temperature with the supplier before choosing seat and gate coating.

Applications and documents

In the Gulf, comparable duties arise in mineral processing, power-plant ash handling, produced water solids and sludge lines. This is general context; verify every service against the bulletin. See other gate valves in the Knife Gate & Slurry Valves category.

Bulletin 51.00-1A (09/2026) is attached with weights, Cv values and dimensions. Send size, class, body material, seat and the actuator type when requesting a quotation from Seven Star LLC.

Using the KSV in Oman and the GCC

High-pressure slurry isolation is needed in the region’s mining and mineral processing plants, including copper, chromite and limestone operations, as well as in cement plants, power station ash handling and tailings pipelines. In these lines, wear on the gate and seats decides valve life, so the hard-faced gate and rotatable seat rings of the KSV help extend the interval between overhauls.

Before ordering, confirm the solids content, particle size and line velocity, because these affect the choice of trim and the port diameter. Valves on long tailings lines often see pressure surges, so the pressure class should include a margin. Plan access for actuator maintenance and for rotating the seat rings, and keep spare seat rings and packing at site for critical lines.

Sending a photo of the nameplate of any valve being replaced helps us match the face-to-face dimension and the actuator mounting.

Information to send with an enquiry

• Size, pressure class and flange drilling
• Slurry type, solids content, particle size and velocity
• Pressure, temperature and flow direction
• Actuator type and accessories
• Quantity and any spare parts needed