Double-Flange Butterfly Valve

I. Overview of Metal Hard-Sealed Butterfly Valves

The metal hard-sealed butterfly valve D343H features a precision "U"-shaped stainless steel sealing ring, which makes three-dimensional eccentric contact with the polished butterfly disc. This design eliminates the common issue found in traditional eccentric butterfly valves—where the sealing surfaces experience sliding friction even during the critical 0° to 10° opening and closing moments. Instead, it ensures that the sealing surfaces instantly separate as the valve opens and make tight contact immediately upon closure, effectively achieving both quick separation and reliable sealing. As a result, this valve significantly extends service life while delivering superior sealing performance. Due to these exceptional characteristics, the metal hard-sealed butterfly valve is widely used in pipelines carrying corrosive media such as those found in metallurgy, power generation, petroleum, chemical processing, air, gas, combustible gases, and water supply/drainage systems—provided the medium temperature does not exceed 550°C. It serves as an ideal device for precisely controlling flow rates and reliably shutting off fluids. Metal hard-sealed butterfly valves are primarily available in two main types: flanged hard-sealed butterfly valves and lug-type hard-sealed butterfly valves.

1. The metal hard-sealed butterfly valve features a triple-eccentric sealing design, ensuring minimal wear between the valve seat and the disc, while delivering a self-tightening sealing action as it closes further. 2. The sealing ring is made from stainless steel, combining the benefits of both metal hard sealing and elastic sealing. This design provides excellent sealing performance—both in low-temperature and high-temperature conditions—along with outstanding corrosion resistance and an exceptionally long service life. 3. The sealing surface of the disc is built up with cobalt-based hard alloy welding, offering superior wear resistance and significantly extending the valve's operational lifespan. 4. For larger-sized discs, a truss structure is employed, providing high strength, a large flow area, and remarkably low flow resistance. 5. This valve boasts bidirectional sealing capability, allowing for installation regardless of the medium’s flow direction or spatial orientation—making it versatile enough to be mounted in any position.

II. Metal Hard-Sealed Butterfly Valve – Key Technical Parameters

3. Metal Hard-Sealed Butterfly Valve – External Connection Dimensions

IV. Installation Precautions for Metal Hard-Sealed Butterfly Valves

Butterfly valves feature a simple design, compact size, and lightweight construction, with relatively few components—just a handful of key parts are needed to assemble the valve. They’re also incredibly easy to operate: simply rotate the handle to a 90-degree position to open or close the valve. Moreover, butterfly valves offer excellent control over fluid flow, allowing users to smoothly adjust the flow rate—either increasing or decreasing it as needed. Of course, like any valve, there’s always some resistance when transporting fluids—but for butterfly valves, this resistance primarily stems from the valve itself, such as the thickness of the valve body. If you want to minimize this resistance, all you need to do is reduce the valve’s thickness.

Elastic seals, however, have the drawback of being limited by temperature.

Butterfly valves have a wide range of applications. If used to control flow, it’s important to select the appropriate type and size of valve body, as butterfly valves are inherently well-suited for larger-diameter applications. Beyond general industrial sectors like oil, gas, chemicals, and water treatment, butterfly valves are also widely employed in cooling water systems at thermal power plants.

1. During installation, the valve disc must be stopped in the closed position.

2. The opening position should be determined based on the rotation angle of the butterfly plate.

3. For butterfly valves equipped with a bypass valve, the bypass valve should be opened first before starting to open the main valve.

4. Installation should be carried out according to the manufacturer's installation instructions. For heavy butterfly valves, a sturdy foundation must be provided.

Note: The dimensions in the table are listed without standard accessories. Additionally, please note that product improvements and technological innovations may lead to slight variations in specifications—please contact our technical department for the latest data.