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Clarkson KS1 Severe Service Knife Gate Valve
Emerson’s Clarkson KS1 is a true bi-directional, zero-leakage ASME Class 150 knife gate valve designed for the rigors of severe service applications. The KS1 is engineered to extend valve life and service intervals, and lower total cost of ownership.
Clarkson KS1 Severe Service Knife Gate Valve


NPS 2 - 16 (DN 50 - 400)
Operating Temperature
Up to 250°F (120°C)
Pressure Class
ASME Class 150
Mining and Minerals, Oil Sands, Pulp and Paper, Coal Preparation, Power, Steel
CRN (pending)
Design To
Face to Face
MSS SP-135
Flange Drillings
ASME 150/300, AS Table D/E, PN 10/16/25


  • ENSURE TIGHT SHUTOFF – Deploy a patented gate edge seal that creates a continuous seal around the gate, together with a precision-molded elastomer seat to deliver zero leakage. This heavy duty, replaceable seat increases the contact area and resilient sealing ability of the valve compared to standard O-ring designs, resulting in superior isolation performance over an extended lifecycle.
  • IMPROVE THROUGHPUT – Run your processes for longer with a valve design optimized to thrive in heavy slurry conditions. A full round port eliminates protrusions into the flow, minimizing turbulence across the valve to extend body life. This not only ensures the longevity of sealing components, but also minimizes the damaging impacts of slurry on downstream pipeline equipment.
  • MINIMIZE WEAR – Extend the life of your valves with standard inlet and outlet hardened wear rings to protect the sealing elements and body from abrasive slurry. These durable Ni-Resist rings can be rotated 3 times through 4 positions to extend valve life and replacement intervals, allowing you to improve your asset utilization and process productivity.
  • SIMPIFY MAINTENANCE – Minimize valve repair downtime with external packing adjustments that dynamically self-adjust compression in the gate edge seal system. Repairs can be performed rapidly using standard tools and readily available spare parts. The valve is also designed to MSS-SP-135 face-to-face dimensions for simple changeout and upgrade of your underperforming installed valves.