BI-DIRECTIONAL MSS SP-81 KNIFE GATE VALVE
Bi-directional MSS SP-81 lug type knife gate valve for general industrial and water applications
Bi-directional MSS SP-81 lug type knife gate valve for general industrial and water applications
The knife gate is a bi-directional lug type valve designed according to MSS-SP-81 and TAPPI TIS 405-8 for industrial service applications.
The design of the body and seat assures non-clogging shut off on suspended solids in industries such as:
- Pulp and Paper
- Power plants
- Mining
- Chemical plants
- Wastewater
- Food and Beverage
DN 2"/50 to DN 36”/900 (larger diameters on request)
WORKING PRESSUREDN 2"/50 to DN 24”/600: 150psi / 10 bar
DN 30"/750: 100psi / 7 bar
DN 36"/900: 100psi / 7 bar
STANDARD FLANGE CONNECTIONASME B16.5 (class 150)
OTHER FLANGE CONNECTION (ON REQUEST)
Bi-directional knife gate valves provide tight shut-off against pressure from either flow direction, making them essential for installations where the valve may see reverse pressure — typical examples include pump suction service, headers feeding multiple branches, bidirectional transfer lines, and water distribution networks where flow reversal can occur during system upsets or pump cycling.
The bi-directional seat design uses a resilient elastomer seat that seals against the gate face on both sides, eliminating the directional installation concern that uni-directional valves require. This design is widely specified in municipal water and wastewater systems, mining process water, slurry transfer lines, and any application where the cost of a misinstalled valve outweighs the modest price premium over a uni-directional unit. MSS SP-81 and TAPPI TIS 405-8 compliance ensure interchangeability with industry-standard piping systems. Lug body construction supports dead-end service, and a range of seat compounds is available to match specific media chemistry — EPDM and Buna-N for water and general industrial service, Viton for chemical compatibility, and PTFE-faced options for severe service.
