The double-eccentric butterfly valve is an enhanced high-performance valve developed based on the single-eccentric butterfly valve. Its core design feature lies in the valve stem axis being simultaneously offset from both the disc center and the valve body center, forming a dual-eccentric structure. This design significantly improves sealing performance, pressure resistance, service life, and throttling capability compared to conventional butterfly valves. As a result, it is widely used in industries such as chemical processing, power generation, water supply and drainage, and metallurgy.
Structural Features
Soft Seal:
Utilizes rubber, PTFE, or other elastomeric materials, suitable for medium/low-temperature and low-pressure applications, offering exceptional sealing performance.
Metal Hard Seal:
The valve seat and disc sealing surfaces are overlaid with stainless steel or hard alloys, designed for high-temperature/high-pressure environments (e.g., steam pipelines) while complying with fire safety standards such as API 607.
Double-Eccentric Design:
The valve stem axis is offset from both the disc center (primary eccentricity) and the valve body sealing surface center (secondary eccentricity). This enables the disc to immediately disengage from the seat during opening, minimizing sealing surface friction and wear.
Sealing Configuration:
Valve Body & Disc: The body is typically cast steel or stainless steel, with a circular disc driven by actuators (electric/pneumatic).
Working Principle
Opening Process:
The actuator rotates the valve stem, and the double-eccentric design allows the disc to rapidly separate from the seat, reducing friction for swift opening.
Closing Process:
As the disc rotates to the closed position, the eccentricity ensures gradual sealing surface compression, achieving reliable shut-off.
Flow Regulation:
By precisely controlling the disc rotation angle (0°–90°), fluid flow can be accurately adjusted.
