SUPCON BN Series Triple Off-set Butterfly Valve

BN series of triple eccentric butterfly valve, the valve plate adopts three-dimensional eccentric structure, opening and closing, the valve seat and disc plate almost no friction disc plate sealing ring for multi-layer stainless steel and graphite composite plate sealing ring, sealing performance is excellent, the valve size is big, small operation torque, small flow resistance, reliable sealing, suitable for large diameter and low flow resistance, the operation condition of the leakage is small.

Product Description

Triple Offset Butterfly Valve

A Triple Offset Butterfly Valve is a specialized type of butterfly valve that is designed to provide reliable and bubble-tight shut-off in high-pressure and high-temperature applications. It is called "triple offset" because the valve's sealing mechanism involves three distinct offsets in its design.

The three offsets in a Triple Offset Butterfly Valve refer to the following:

First Offset: The shaft is offset from the center of the valve body, which ensures that the valve disc (also known as the butterfly) makes contact with the seat only at the final stage of closing. This design reduces friction during valve operation, preventing unnecessary wear and tear.

Second Offset: The center of the valve disc is offset from the centerline of the pipe. This offset, combined with the conical shape of the valve seat, allows for a cam-like action during closing. As the disc comes in contact with the seat, it moves perpendicular to the seat's sealing surface, achieving a tight and uniform seal without excessive rubbing.

Third Offset: This offset refers to the cone angle of the sealing surface on the valve disc. The cone angle is different from the cone angle of the valve seat. This design creates a "wedging" effect during closing, ensuring a tight and bubble-tight seal even at high pressures and temperatures.

Benefits of Triple Offset Butterfly Valves:

Bubble-Tight Shut-Off: The triple offset design provides a reliable, tight seal, preventing any leakage or bubble formation, even in demanding conditions.

High-Performance: These valves are capable of handling high-pressure and high-temperature applications, making them suitable for critical processes in various industries, such as oil and gas, petrochemical, power generation, and more.

Minimal Wear: The offset design reduces friction and wear on sealing surfaces, leading to a longer service life and lower maintenance requirements.

Bi-Directional Sealing: Triple offset butterfly valves can effectively seal in both flow directions, offering flexibility in installation and operation.

Reduced Torque and Actuation Effort: The design reduces the torque required to operate the valve, making it easier to actuate, especially in larger sizes.

Due to their superior performance and reliability, triple offset butterfly valves are frequently used in applications where traditional butterfly valves or other valve types might not provide the necessary level of tight shut-off or operational efficiency.


Nominal SizeDN80~DN1600
Pressure RatingPN16/PN25/PN40; CL150(PN20)/CL300(PN50)
Operateing Temperature-20℃~425℃
CharacteristicsApproximate equal percentage
Seat Leakage ClassZero Leakage
Body MaterialWCB/WCC/LCB/LCC;WC6/WC9;CF8/CF8M;4A/5A etc.
Trim MaterialMetal:304+SN/304+SN;304+ST/304+ST;Soft:304+HCr/RTFE
Seal MaterialPTFE, Flexible graphite