Features and Advantages
Stem Blow Out Prevention Ring
Prevent stem ejection in accidental working situation.
Replaceable Disc Seal
Reduce field maintenance costs.
Live Loading Packing Gland
Standard low emission stem seal with 0-20 PPM live-loading provides predictable and constant packing compression for more than 5000cycles before adjustment or re-packing.
Metal-to-Metal Patented Sealing System
Stellite Alloy HRC 40-60 degree centigrade
Disc Position indication
Stem end provides fool-proof verification of disc location.
Actuator Mounting Plate and Stem Connection conform to ISO5211
Principle Of Operation
The SDF Triple Offset Butterfly Valve provides a bi-directional bubble tight shut-off. This geometry ensures that the disc seal contacts the body seat only at the final shut-off position without rubbing or galling, providing a torque generated resilient seal with sufficient“wedging”to ensure a uniform seal contact.
THE TRIPLE OFFSET GEOMETRY
OFFSET 1 The shaft is offset behind the seat axis to allow complete sealing contact around the entire seat.
OFFSET 2 The shaft centerline is offset from the pipe and valve which provides interference free opening and closing of the valve.
OFFSET 3 The seat cone axis is offset from the shaft centerline to eliminate friction during closing and opening and to achieve uniform compressive sealing around the entire seat.