Double Offset Butterfly Valve

Basic properties
○ double offset design
○ eccentric disc position in the body, precise connection of the disc with the stem and pivot, exact shaft and pivot bearing in the slide bushings
○ split sealed stem - bigger Kv
○ high efficiency of opening and closingvalve
○ vacuum max. 0,01 bar abs
○ standardized top flange according to EN ISO 5211 enabling mount various types of actuator (electric, pneumatic, hydraulic)

Double offset
The double offset design provides a safe function and tightness even after a sudden temperature or pressure change. It reduces seat wear and ensures perfect tightness. The first offset shifts the axis of the rotation off the sealing surface and thus provides tightness between the seat and the sealing ring around the entire disc circumference. The second offset moves the the axis of the disc rotation off the valve (pipeline) axis and thus releases the ring from the seat after a few degrees of opening movement. The reason of the second offset is to quickly relieve the seal from compression between the disc and the seat.

Advantages of double offset valves
○ lower pressure loss
○ split stem allows higher Kv/Cv values
○ actuator connection can be done bybracket or the stem can be extended if connected to special actuator types
○ low closing torque
○ the seal guarantees perfect upper stem tightness
○ sealing ring and seat come to contact only nearly after the valve is entirely shut

Seal design
R-PTFE - suitable seal geometry ensures full tightness and a high number of cycles. The PTFE seal is reinforced with 30% carbon fibres, reducing wear and and increasing valve thermal stability. Longer lifespan of the valve and lower maintenance demand are guaranteed.