D643Y all-metal hard-seal butterfly valve is a metal-sealed valve specially used for high-temperature and high-pressure working conditions. It drives the butterfly plate to perform a 90° rotary motion through worm gear and worm transmission combined with a pneumatic actuator to realize the on-off of pipeline medium and flow regulation. The valve adopts a triple eccentric structural design with a flange connection type. The sealing pair is composed of matched hard metal alloys. The sealing surface of the butterfly plate is surfacing welded with cobalt-based and nickel-based hard alloys, and the valve seat is also equipped with a metal hard sealing surface, which achieves tight fitting relying on the mechanical structure of triple eccentricity. The transmission mechanism amplifies torque through worm gear deceleration and pushes the valve stem to drive the butterfly plate to rotate and close. Featuring high temperature resistance, high pressure resistance, erosion resistance and wear resistance, the metal hard-seal structure is suitable for high-temperature and high-pressure media with no strong corrosion or weak corrosion such as steam, high-temperature flue gas, hot oil, high-temperature gas and pulverized coal flue gas. It is widely applied in pipeline control systems under severe working conditions including thermal power plants, metallurgy, heating pipe networks, petrochemical high-temperature pipelines, HVAC boilers and other fields.

Features

1、Triple-eccentric metal hard-seal structure Adopts multi-layer triple-eccentric mechanical design. The sealing pair consists of metal-to-metal hard alloy surfaces. There is no friction between the disc and valve seat, resulting in minimal abrasion during opening and closing, together with long-lasting sealing stability.

2、 Adaptable to high/low temperature and high-pressure conditions The metal sealing material boasts outstanding pressure bearing capacity. Standard nominal pressure ranges include PN16, PN25, PN40 and higher grades. Operating temperature spans from -40℃ to 650℃, enabling long-term service for high-temperature steam and flue gas working environments.

3、 Erosion & wear resistance with extended service life High-strength hard alloy is hardfaced on sealing surfaces, delivering excellent resistance to particle scouring and friction. The sealing surfaces remain intact even when media contains dust and fine particulate impurities, making the valve ideal for particle-laden media such as flue gas, pulverized coal and heat transfer oil.

4、 Flexible compatibility with multiple actuators Comes standard with worm gear manual operation. Electric or pneumatic actuators can be fitted for remote automatic control. It accepts on-off and modulating signal control, matching complete industrial automatic control systems.

5、 Reliable bi-directional pressure sealing The triple-eccentric design delivers equal sealing performance in both flow directions with no restriction on pressure flow direction. The highest sealing class reaches Class VI with zero internal leakage under high pressure.

6、 High-rigidity flanged valve body with stable connection Full flanged connection design. Valve bodies are commonly manufactured from carbon steel, stainless steel and alloy steel. The robust housing resists pipeline stress and high-pressure deformation, maintaining structural integrity under long-term high-temperature and high-pressure operation.

7、  Superior flow capacity with moderate flow resistance Unobstructed butterfly passage creates lower pressure loss than gate and globe valves. It performs exceptionally well in large bore sizes, offering remarkable energy savings for high-flow conveying applications.

8、 No fluoroplastic lining; unsuitable for strong corrosives, fits clean high-temperature media No PTFE lining is equipped, so the valve cannot withstand strong corrosive media like concentrated strong acids and alkalis. Without plastic lining, there is no risk of softening or aging at high temperatures, nor peeling of sealing layers during prolonged high-temperature operation. Disassembly and maintenance are convenient; sealing surfaces can be repaired via on-site hardfacing, keeping maintenance costs manageable.

                                                            Structure Diagram of D343Y All-metal Hard-seal Butterfly Valves

Parts Name and Materials List

Performance Specification Table

                                                                            D343Y All-metal Hard-seal Butterfly Valves Overall Dimension Drawing

D343Y All-metal Hard-seal Butterfly Valves overall dimension table

Due to the rapid R&D iteration speed of valve products from China Kaivex Valve Group Co., Ltd., the above technical parameters and specification documents, including product overview, features, parts materials, outline dimension charts, CAD drawings, and product instruction manuals, are for your reference only. For actual applications, please contact our valve sales engineers to obtain the support you need for free. Thank you!