Manual Stainless Steel Flange-Type Metal Hard Seal Butterfly Valves

The Manual Stainless Steel Flange-Type Metal Hard Seal Butterfly Valves are on-off and control valve suitable for harsh industrial conditions. Constructed primarily from stainless steel for pressure-bearing and media-contact components, it features a triple-offset design and metal hard-seal structure. The valve is operated manually to rotate the disc, providing reliable shutoff and throttling of pipeline media. Its well-proven structure and optimized force distribution ensure stable performance under high temperature, high pressure, and corrosive environments. In international markets, this product is commonly referred to as a Manual stainless steel flange-type metal hard seal butterfly valves and is widely used in petrochemical, power, and metallurgical systems.

Structural Features and Working Principle

The Manual Stainless Steel Flange-Type Metal Hard Seal Butterfly Valves adopts a classic triple-offset design, which allows the disc to gradually disengage from the seat during opening and closing, significantly reducing friction and wear. The metal hard-seal is made of stainless steel or alloy materials, and the sealing face can be reinforced with Stellite or nickel-based alloy overlay welding to maintain excellent sealing performance even under high-temperature and high-pressure conditions. The flange end face is machined according to GB or ANSI standards, ensuring good alignment during installation and facilitating on-site maintenance. This type of Manual stainless steel flange-type metal hard seal butterfly valves is operated via a handwheel or lever, offering straightforward structure and high reliability.

Key Product Features

• All-stainless steel construction provides excellent corrosion and oxidation resistance

• Metal hard-seal design suitable for high temperature, high pressure, and abrasive media

• Triple-offset structure reduces operating torque and extends service life

• Flange connection ensures stable installation and compatibility with various piping systems

• Manual operation enables simple maintenance and controlled operation

Typical Applications

The Manual Stainless Steel Flange-Type Metal Hard Seal Butterfly Valves is widely used in high-temperature medium pipelines in petrochemical plants, steam systems in the power industry, flue gas and dust pipelines in metallurgy, and corrosive medium systems in water treatment and papermaking industries. In these demanding environments, the Manual stainless steel flange-type metal hard seal butterfly valves maintains stable operation despite frequent temperature changes and complex media conditions.

Main Technical Parameters

• Nominal diameter: DN50–DN600 (NPS 2"–24")

• Pressure rating: PN10/16/25/40, Class 150/300/600

• Connection: Flange (GB/T 9113 / ANSI B16.5 RF)

• Operation: Manual (handwheel/lever)

• Temperature range: -46℃ ～ 550℃

• Leakage class: Class V (API 609)

• Structure: Triple-offset metal hard-seal

Material Configuration

The valve body and disc can be made of 304, 316, 304L, 316L, or 2205 duplex stainless steel to meet different corrosion resistance requirements. The valve stem is typically made of forged stainless steel or duplex steel for a balance of strength and toughness. The seat and sealing face are selected based on operating conditions and can be stainless steel, Stellite, or nickel-based alloy to ensure reliable metal sealing.

Selection and Usage Recommendations

When selecting a valve, factors such as medium properties, design pressure, and temperature should be carefully considered, and the flange standard must match the existing piping system. For large-diameter or high-pressure applications, the manual operating torque should be evaluated, and a torque-reducing mechanism may be necessary. Proper installation and regular maintenance will effectively extend the service life of the Manual stainless steel flange-type metal hard seal butterfly valves.

Maintenance and Operation Management

It is recommended to establish comprehensive operation and maintenance records, and to regularly inspect flange connections, stuffing boxes, and sealing surfaces. In high-temperature or corrosive environments, enhanced lubrication and anti-corrosion measures should be implemented to ensure long-term stable operation and provide reliable protection for system safety.