Overview and Application
Triple-eccentric all-metal hard-sealed butterfly valves are widely used in various applications requiring active shut-off. The quarter-turn design and ultra-low operating torque also facilitate precise flow and pressure control. The true shutoff and regulating capabilities of our valves allow a single product to be achieved where two different valves would normally be required. In addition, low torque also means low actuator costs.
Today, compared to traditional process valves, our triple-eccentric all-metal hard-seal butterfly valve takes an important step forward. Although they use the same cone-in-cone sealing mechanism as globe valves, the sealing has been replaced by quarter-turn rotation. The quality, robustness, durability and reliability of our MTM range, including its key contribution in automatic emergency shutdown, are ultimately the result of precise risk analysis applications and are based on our four fundamental product design features:
Torque seal
BOLON's sealing force is generated by externally applied torque, rather than by mechanical interference as in position-sealing ball valves, butterfly valves and plug valves. This means that the cone-in-cone seal is created by contact pressure rather than friction caused by the elastic deformation of the valve seat. This feature enables our valves to handle high pressure levels and provide reliable and highly controlled operating torque.
Metal to metal seal
BOLON's cone-in-cone concept requires metal-to-metal sealing to handle more demanding applications. We use Stellite 21 as the seat material and duplex stainless steel with high mechanical properties as the elastomeric sealing ring in the low configuration. Stellite 21 A cobalt alloy overlay welded onto the valve seat, providing sufficient hardness and resistance to fluid wear while ensuring high corrosion resistance. Due to its unique design, the metal seal ring has elastic properties to be compressed evenly around the sealing surface in the radial direction.
Angular stroke rotation
Thanks to the sealing element that remains in place and rotates around its own axis, BOLON valves save customers valuable space and have a lower and more consistent operating torque than other valves with poppet stems. Significantly improve its operability. In addition, quarter-turn rotation eliminates the negative effects of a lift stem on the packing, such as squeezing and wear, improving valve performance and reducing fugitive emissions.
frictionless rotation
Eliminating contact between the valve seat and sealing ring during opening-closing means extended seal and valve life. BOLON valves also have the main characteristics of quarter-turn rotary valves, such as low and consistent operating torque, which allows the valve to always maintain quick and easy operation, even at very low angles. This feature makes our triple offset valve an ideal solution for any application requiring emergency shut-off, venting or frequent cycling operations (such as molecular sieves).
Technical Parameters
Material: carbon steel, high temperature alloy steel, austenitic stainless steel,
Duplex and Super Duplex Stainless Steels and More
Size range: DN80 to ON3000
(NPS 3 to NPS 120)
Connection method: double flange, clamp, lug, butt welding
Pressure Class: ASME 150-2500; EN PN 6-420
Temperature range: -254°C to 815°C (-425° F to 1500° F)