API 609 Triple Offset Butterfly Valve is an improved version of the double offset butterfly valve. The term "triple offset" refers to the addition of an angular offset to the double offset (where the stem axis is offset from both the disc center and the body centerline). This results in a sealing surface that is conically inclined.
In this design, the outer periphery of the disc is machined into an outer inclined conical surface, while the inner side of the sealing seat is machined into an inner inclined conical surface. This configuration not only increases the contact area between the seat and the disc but also enhances sealing performance.
Working Principle
The operation of a Triple Offset Butterfly Valve primarily relies on its three offset designs. When opening or closing, the disc rotates 180° on the seat. Due to the three offsets, the disc quickly disengages from or presses against the seat sealing surface during rotation, enabling frictionless or low-friction opening and closing. Additionally, since the sealing surface is conically inclined, the disc-divided by the stem axis-applies pressure to the seat along different inclined curves, further enhancing sealing performance.
Specification
Butterfly valve design according to API609, ASME B16.34
Face to face ASME B16.10/API609
End Flanges ASME B16.5/ASME B16.47
Ends :Flange ,Wafer or Lug
Inspection and test API 598
Material: WCB
Size Range: 2″~60″
Pressure Rating: ASME CL, 150, 300, 600
Temperature Range: -29°C~425°C
Features & Advantages
Excellent sealing performance – The three offsets significantly improve sealing effectiveness, ensuring reliable performance even under high temperature, high pressure, or corrosive media conditions.
Wear-resistant – The three-offset design allows the disc to self-grind during operation, reducing wear and extending valve lifespan.
High adaptability – With a simple structure, easy operation, and excellent high/low-temperature resistance, the valve maintains stable performance in diverse operating conditions.
Lightweight operation – The frictionless/low-friction opening and closing mechanism ensures smooth and effortless operation.
