Series GRF (ISO)

Resilient SeatedKeystone

A heavy duty double flanged concentric design resilient seated butterfly valve

These valves are for water or air service where a drop-tight shut-off and double flanged body are required.

  • 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.
  • Actuator flange according to ISO 5211.
  • 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.

Technical Data


Resilient seated

Supply pressure:

Up to 145 psi


-18°F - +320°F


NPS 24-72


Double flanged - centric



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