Overview

The D343H hard seal butterfly valve is a flanged connection butterfly valve that utilizes a multi-layer metal hard sealing structure and achieves tight shut-off through the triple eccentric principle. This valve features a triple eccentric geometry comprising axial eccentricity, radial offset, and conical angle eccentricity. This design ensures that the disc completely disengages from the metal seal ring during the opening and closing cycles, creating a wedge-type compressive seal only at the final closed position. The valve stem is operated via a worm gear mechanism, offering easy operation and self-locking functionality. The sealing pair consists of a laminated structure of stainless steel sheets and flexible graphite, or a hardfaced alloy on the disc sealing surface. This forms a high-hardness, wear-resistant hard sealing system against the metal seat, making the valve suitable for demanding conditions involving high temperatures, high pressures, and media containing solid particles.

D343H Triple Eccentric Hard Seal Butterfly Valve Product Image

Features

1、Multi-layer Metal Hard Seal: The sealing pair consists of an elastic sealing ring made of laminated stainless steel sheets and flexible graphite, or features a hardfaced alloy on the disc surface. This creates a multi-layer seal that is wear-resistant, high-temperature resistant, and offers a long service life.

2、Triple Eccentric Structure: Through precisely calculated triple eccentric design, the disc completely disengages from the seal ring at the moment of opening, achieving zero friction during rotation. Upon closing, it utilizes the eccentricity to create a progressive wedging action, ensuring reliable sealing with low operating torque.

3、High Temperature and Pressure Resistance: The metal sealing structure allows the valve to operate long-term under high temperatures up to 425°C, with pressure ratings up to PN16~PN40. It is suitable for industrial media such as steam, heat transfer oil, and high-temperature flue gas.

4、Erosion and Corrosion Resistance: The hard sealing surface effectively resists erosion and corrosion from solid particles, crystals, or mildly corrosive components in the medium. The valve body cavity can be coated with anti-corrosion coatings to extend the overall service life.

5、Bidirectional Zero Leakage Seal: Leveraging the self-energizing effect of the eccentric structure, the valve achieves a metal-to-metal seal under both forward and reverse pressure, resulting in bidirectional zero-leakage performance. Installation is not restricted by media flow direction.

6、Long Life, Low Maintenance Design: The worm gear drive operates smoothly and reliably. The highly wear-resistant hard sealing pair enables long-term maintenance-free operation under normal conditions. This makes it particularly suitable for critical processes in industries such as power generation, metallurgy, and chemical engineering where high reliability is required.