UNI-DIRECTIONAL MSS SP-81 KNIFE GATE VALVE
Uni-directional MSS SP-81 lug type knife gate valve for general industrial applications
The knife gate is a uni-directional lug type valve designed according to MSS-SP-81 and TAPPI-TIS 405 for industrial service applications.
The design of the body and seat assures non-clogging shutoff on suspended solids in industries such as:
- Pulp and Paper
- Power plants
- Mining
- Chemical plants
- Wastewater
- Food and Beverage
- etc.
SIZESDN 2"/50 to DN 36"/900 (larger diameters on request)
WORKING PRESSUREDN 2"/50 to 24"/600: 150 psi (10 bar)
DN 30"/750: 100 psi (7 bar)
DN 36"/900: 100 psi (7 bar)
STANDARD FLANGE CONNECTIONEN1092 PN10
NSI B16.5 (class 150)
OTHER FLANGE CONNECTION (ON REQUEST)
Uni-directional knife gate valves are designed for service applications where flow and shut-off pressure act in a single, predictable direction — most commonly downstream from a pump or above a gravity-fed tank or hopper. The seat geometry on a uni-directional valve provides a tight shut-off in one direction while allowing the gate to lift cleanly through the slurry on opening, making this style the workhorse choice for pulp and paper stock lines, mining tailings transfer, wastewater sludge handling, and dry-bulk powder isolation.
Compared to bi-directional designs, uni-directional knife gates typically carry a lower price point and exhibit lower operating torque, which translates to smaller actuators and reduced lifetime energy cost when the valve is automated. Lug body construction supports dead-end service and allows downstream piping to be removed without depressurizing the upstream system. MSS SP-81 compliance ensures dimensional and pressure-rating consistency with industry standards, and TAPPI TIS 405 conformance addresses the specific requirements of pulp and paper stock service.
