The Keystone GRF is a Double Flanged Butterfly Valve for heavy duty. The Keystone Series GRF comes with a concentric design and is resilient seated. The Keystone GRF Butterfly Valves are used in water or air service where a drop-tight shut-off and double flanged body are required.
Features
Double flanged body design with face-to-face dimensions, according to EN 558 Series 20, API 609 and AWWA C504 short
Designed according to EN 593 and API 609
The seat is field replaceable and fully isolates the body and shaft from the flow
Primary shaft sealing exceeds the pressure rating of the valve and prevents leakage through shaft area to atmosphere
A secondary shaft sealing provides back-up safety
A molded-in O-ring in the seat for flange sealing eliminates the need for gaskets
Shaft seals prevent moisture penetrating into the shaft area
Rounded polished disc edge gives full concentric sealing, lower torques, longer seat life and drop-tight shut-off
Extended body neck allows for pipe insulation
Top and bottom shaft bearings for optimized support and minimum friction and decreased torque
Top bushing absorbs actuator side thrust loads
All Valves comply to Pressure Equipment Directive (97/23/EU) Module B1 + D, CE Marking.
Available approvals: ABS, NSF/ANSI STD 61
