Five-Eccentric Metal Seated Butt-Welded Butterfly Valve

Five‑Eccentric Butt‑Welded Butterfly Valve, also known as Quintuple Offset Butt‑Welded Butterfly Valve, is a high‑performance butterfly valve further optimized and developed on the basis of conventional triple‑offset butterfly valve technology.

This valve adopts an innovative quintuple‑offset structure and Heteromorphic Spherical Sealing System. By optimizing the spatial geometric relationship among the stem axis, disc rotation center and sealing face, it achieves superior friction‑free movement and non‑contact sealing during opening‑closing cycles.

Compared with traditional butterfly valves, the quintuple‑offset design further minimizes mechanical friction between the disc and sealing faces, delivering lower operating torque in both opening and closing operations. Meanwhile, the special heteromorphic spherical sealing structure realizes self‑cleaning effect on sealing surfaces via the disc’s rotating trajectory. It reduces retention of particulate matter and impurities in the sealing zone, so as to improve sealing stability and extend service life.

Working Principle of Quintuple Offset Butt-Welded Butterfly Valve
Definition of the Five Offsets:

• ① Stem Axis Offset: The valve stem axis is offset from the centerline of the pipe. This geometry allows the disc to disengage rapidly from the sealing surface upon initial opening.
• ② Disc Rotation Center Offset: The rotational center of the disc is offset from the centerline of the valve body. This minimizes friction during the disc’s opening and closing stroke.
• ③ Sealing Taper Offset: The center axis of the sealing surface is spatially offset from both the stem and rotational axes. This results in a non-frictional sealing motion during operation.
• ④ Sealing Surface Geometric Offset: The traditional conical/elliptical cone geometry is further optimized to improve the sealing contact pattern and optimize the stress distribution across the sealing faces.
• ⑤ Non-Spherical Spatial Offset: A specialized non-spherical sealing trajectory is employed to establish an asymmetric spatial relationship between the sealing surfaces. This unique geometry ensures ultra-low friction, stable sealing performance, and an inherent self-cleaning effect on the sealing faces.

Opening Process: The actuator drives the stem to rotate, initiating disc movement from the fully closed position. Benefiting from the patented quintuple offset non-spherical geometry, the disc disengages entirely from the metal sealing faces within an extremely short rotational angle at the beginning of the stroke. Throughout the entire opening stroke, there is zero mechanical friction or abrasion between the sealing pairs. This eliminates the continuous grinding friction typical of conventional butterfly valves, significantly reducing the required operating torque. Moreover, the self-cleaning sealing geometry allows the flowing medium to effectively sweep away any accumulated dust, particles, or debris from the sealing surfaces during operation. As the disc continues rotating to the fully open position (approximately 90°), it aligns nearly parallel with the flow direction, thereby maximizing the flow area and minimizing pressure drop across the valve.

Closing Process: The actuator reverses the direction of the stem to rotate the disc back toward the closed position.
The tight seal is only engaged during the final stage of the closing stroke. At this point, the cam-like wedging effect, generated by the quintuple offset geometry, gradually forces the disc sealing face against the non-spherical metal seat. This progressive engagement establishes a uniform and sufficient sealing specific pressure, ensuring a reliable, bubble-tight metal-to-metal hard seal. Once fully closed, the valve completely isolates the upstream and downstream flow, providing absolute positive shut-off and reliable pipeline isolation.