Triple Eccentric Fully Welded Butterfly Valve

Triple Eccentric Welded Butterfly Valve is a high‑performance industrial butterfly valve featuring triple‑offset geometry, metal hard‑seal and butt‑weld connection, mainly designed for high‑temperature, high‑pressure, low‑temperature and severe industrial service conditions.

Triple offsets are applied to the stem axis, disc rotation center and geometric center of the sealing face, enabling virtually friction‑free or low‑friction movement between disc and seat during opening‑closing cycles. Upon valve closure, the cam‑style rotating trajectory gradually presses the disc against the metal sealing ring to achieve reliable metal hard sealing. When opening, the disc lifts off the sealing surface rapidly, which reduces operating torque and wear on sealing faces.

Working Principle of Triple‑Offset Fully‑Welded Butterfly Valve
Triple‑Offset Geometry：

• 1st Offset: The stem axis is offset from the valve body centerline.
• 2nd Offset: The stem axis is further offset from the centerline of the disc sealing face.
• 3rd Offset: The seat sealing face adopts a tapered geometric configuration to create a unique angular relationship for the sealing interface.

Opening Stroke：The actuator drives the valve stem to rotate, and the disc moves from the closed position towards the open position. Benefiting from the triple‑offset design, the disc lifts off the metal sealing surface at the initial opening stage. It avoids continuous rubbing against the seat throughout the full rotation travel, which commonly occurs in conventional butterfly valves. As the disc continues rotating, the flow passage opens progressively. When the disc approaches the 90° fully‑open position, it is substantially parallel to the medium flow direction. The flow‑through cross‑section is enlarged for smooth medium passage.

Closing Stroke：The actuator drives the valve stem to rotate in reverse, and the disc moves gradually toward the closed position. Near the closed position, the disc travels toward the seat along a special offset trajectory. The disc sealing face gradually contacts the metal sealing ring and generates sufficient sealing specific pressure. When the disc is fully closed, the metal‑to‑metal sealing interface forms a tight seal to shut off the pipeline medium.