Double Offset Butterfly Valve

Double Offset Butterfly Valve

The Double Offset High-Performance Butterfly Valve is a new type of butterfly valve designed by absorbing the advantages of several different structural butterfly valves. The sealing surface of the valve plate is a spherical arc surface. The sealing mechanism achieves a true dynamic seal through system pressure, thus providing reliable sealing performance and durability. It features a small volume, light weight, wide manufacturing range, and is easy to maintain and repair. Due to its double offset butterfly plate design and single-piece flexible lip-shaped sealing seat, it is ideal for applications requiring reliable sealing and good regulating characteristics. It can be used for quick shut-off or regulating flow.

Double Offset Frictionless Design

• 1st offset: Shaft is positioned downstream from the centerline of the seat.
• 2nd offset: Shaft is off center from the vertical axis of the seat.
• ISO 5211 Top Flange
• In addition to standard, durable V-ring packing, you can also choose from optional graphite
• high temperature packing or emissions control packing.
• Bi-Directional, Shut off performance
• Seat Options: Rubber, PTFE, RPTFE, or Fire Safe PTFE
• The double offset operating principle minimizes seat wear and lowers operating torque to
• improve durability.
• Positive sealing is mechanically achieved and does not rely on line pressure assistance.

Seat Structure

Double Offset PTFE Seat Butterfly Valve

• A surplus of material between the PTFE Seat and Disc ensures a reliable seal in a low pressure environment.
• In high pressure situations, the force of the medium pushes against the seat contacting the sealing surface for a stronger seal.
• The disc surface has a conical design to reduce frictional force. The valve seat can also be replaced or repaired easily.

Double Offset Fire Safe PTFE Butterfly Valve

• Fire Safe valve seat with dual seal includes a primary PTFE seat insert and metal seat. 
• In the event that the PTFE insert is destroyed, the secondary metal seat provides an effective shut-off. 

Shaft Retention

• Externally retained, double blowout proof stem design as API 609
• External: Shaft is designed with an integral collar and gland follower to prevent blowouts.

Zero Leakage

• Disc-Seat sealing is achieved by evenly loading torque force onto the disc's laminated seal

ISO 5211 Top Mounting

Different End Connections Available: