Overview
The D343Y Stainless Steel Triple Eccentric Hard Seal Butterfly Valve is a valve that achieves opening, closing, and flow regulation through the rotation of a high-strength stainless steel disc around its fixed axis (valve stem). Its design features a "triple eccentric" structure, meaning the valve stem axis is offset from the center of the disc sealing surface, the centerline of the pipeline, and the center of the valve body. This allows the disc to instantly disengage from or press against the valve seat during opening and closing, completely eliminating friction and binding between the sealing surfaces. The valve adopts a flanged connection for convenient installation and disassembly. Both the disc and valve seat sealing surfaces are made of metallic materials (stainless steel against stainless steel) and are precision-lapped. Relying on the cam effect generated by the triple eccentric structure, the valve achieves a reliable sealing action that tightens as the valve closes. This valve can be operated manually, electrically, or pneumatically, rotating the stem 90° to achieve tight shut-off and precise control in pipelines handling high-temperature, high-pressure, and corrosive media.

D343Y Stainless Steel Triple Eccentric Hard Seal Butterfly Valve product image

特点

1、三偏心零摩擦结构： 采用创新的三偏心设计（轴向偏心、径向偏心、角偏心），使蝶板在启闭旋转过程中，密封面在瞬间脱离或接触阀座，完全消除了传统蝶阀密封副之间的机械摩擦与卡挤，大幅延长了阀门使用寿命，并确保启闭扭矩轻便。

2、硬密封耐高温： 蝶板与阀座密封面均采用不锈钢金属材料（堆焊或整体合金），并经高精度研磨抛光。该设计使其能够耐受高达600℃以上的高温工况，适用于蒸汽、热油及高温烟气等严苛介质。

3、越关越紧的可靠密封： 利用三偏心结构产生的凸轮效应，在阀门关闭时，蝶板密封圈与阀座之间产生自锁式压紧力，实现金属对金属的零泄漏密封（符合API 598标准），且密封性能随介质压力升高而增强。

4、流线型流道，低流阻： 阀体流道设计平滑流畅，蝶板在完全开启状态下几乎不占据流道空间，介质流动接近直通管状态，流体阻力极小，压力损失小，适合高流速和大流量工况。

5、耐腐蚀与长寿命： 阀体主体采用优质不锈钢（如CF8、CF8M、CF3等）铸造，具备优异的抗腐蚀性能。高硬度的金属密封副耐磨、耐冲蚀，确保了阀门在腐蚀性、颗粒性介质中的长期稳定运行。

6、广泛的高端工况适应性： 产品可设计为软密封（对温度要求不高时可选配软密封圈）与硬密封双重结构，但主体为硬密封。适用于石油、化工、电力、冶金、制药以及高温空气、煤气、油气混合等苛刻管路系统，作为调节或截流装置使用。

Features

1、Triple Eccentric Zero-Friction Design: Employs an innovative triple eccentric design (axial offset, radial offset, angular offset). This ensures the sealing surfaces instantly disengage from or contact the valve seat during the disc's opening and closing rotation, completely eliminating the mechanical friction and binding found in traditional butterfly valve sealing pairs. This significantly extends the valve's service life and ensures light operating torque.

2、Hard Seal for High-Temperature Resistance: Both the disc and valve seat sealing surfaces are made of stainless steel metal materials (hardfaced or solid alloy) and are precision ground and polished. This design enables the valve to withstand high-temperature conditions up to 600°C and above, making it suitable for demanding media such as steam, thermal oil, and high-temperature flue gas.

3、Reliable Tighter-as-It-Closes Seal: Utilizes the cam effect generated by the triple eccentric design. As the valve closes, a self-locking compression force develops between the disc seal and the valve seat, achieving a metal-to-metal zero-leakage seal (conforming to API 598 standards). The sealing performance enhances as the medium pressure increases.

4、Streamlined Flow Path, Low Flow Resistance: The valve body features a smoothly designed flow path. When fully open, the disc occupies minimal space within the flow path, allowing the medium to flow almost as through a straight pipe. This results in extremely low fluid resistance and minimal pressure loss, making it ideal for high-velocity and high-flow applications.

5、Corrosion Resistance and Long Service Life: The main valve body is cast from high-quality stainless steel (such as CF8, CF8M, CF3, etc.), providing excellent corrosion resistance. The high-hardness metal sealing pair is resistant to wear and erosion, ensuring long-term stable operation in corrosive or particulate-laden media.

6、Broad Suitability for Demanding Applications: While primarily a hard-seal valve, the product can be designed with a dual soft-seal (optional soft seal ring when temperature requirements are lower) and hard-seal structure. It is widely applicable in demanding pipeline systems such as those in petroleum, chemical, power, metallurgy, pharmaceutical industries, as well as for high-temperature air, gas, oil-gas mixtures, serving as a regulating or shut-off device.