Keystone Series GRF (ISO) Butterfly Valves

A heavy duty double flanged concentric design resilient seated Butterfly valve

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.

Application: Cooling Towers, Air Circulation, Cooling Water , Facilities & Process Utilities, Desalination

Material: Duplex, Epdm Rubber, Ductile Iron, Carbon Steel, Buna-N, Aluminum Bronze, 316L Stainless Steel, 316 Stainless Steel, 304 Stainless Steel, Super Duplex