The high-performance DiskFlo Butterfly Valve is used to achieve bi-directional bubble-tight shutoff while maintaining low breakout torque at high and low pressure drops. The high-performance DiskFlo Butterfly Valve uses pressure assisted Jam-lever toggle seating concepts. By utilizing the pressure drop across the valve to aid the seating process, Jam-lever toggle seating assures low breakout torque.
The need for strong actuator seating force is reduced since much of the force is supplied by the fluid pressure. To achieve especially high-performance throttling, even in large pressure drops close to the seat, it is combined with a MASCOT high thrust cylinder actuator and a double eccentric cammed disc.
Soft Seat: To help energize the soft seat to bubble-tight shutoff in either flow direction, including alternating flow applications, Jam-Lever Toggle seating concepts utilize the pressure drop across the valve. Jam-lever Toggle soft seats achieve ANSI Class VI shutoff.
Metal Seat: For applications involving temperatures higher than those permitted by the Jam-lever Toggle soft seat, metal seats are used. A highly flexible lip, which assures full circle contact between the seat and disc when the valve is closed, is incorporated in the design. The lip flexibility permits breakout torque for the metal seat is the same or less than soft seat breakout torque. ANSI class IV shutoff is achieved through DiskFlo metal seats.
Dual Seat: DiskFlo dual seats incorporate both the Jam-lever Toggle soft seat and the flexible lip metal seat for added protection in unclean fluids or demanding applications. It also makes the DiskFlo a Firesafe Butterfly Valve.
DiskFlo Double Eccentric Cammed Disc To lift it out of the seat immediately upon actuation, a double offset has been designed into the disc. This avoids wear on the seat and disc, reducing leakage and parts replacement. The throttling also improves as the friction is eliminated.
Flow Direction Jam-lever Toggle seating allows DiskFlo to flow either shaft downstream or shaft upstream, depending on service conditions. With the shaft downstream the flow tends to open the valve. With the shaft upstream the flow tends to close the valve.
Flow Characteristics The inherent flow characteristic of the DiskFlo valve is a modified parabolic. Other characteristic curves are achievable by means of a MASCOT HiFlo Positioner or a SMART positioner.