A182 F55 WNFF FLANGE, UNS S32760 SUPER DUPLEX STAINLESS STEEL FLANGE
ASTM A182 F55 WN FF Flange is a super duplex stainless steel with high chromium (Cr), molybdenum (Mo), tungsten (W), and nitrogen (N) content, optimized for enhanced corrosion resistance and mechanical strength. FF flanges have a flat sealing surface, typically used with full-face gaskets. They are ideal for low-pressure systems or applications requiring full contact between mating flanges.
Features of ASTM A182 F55 Super Duplex Steel WNFF Flange
- Corrosion Resistance: The duplex microstructure of F55 offers excellent protection against pitting and crevice corrosion.
- High Strength: Provides good mechanical properties, making it suitable for high-stress applications.
- Temperature Tolerance: Designed to handle elevated temperatures, making it versatile for various industrial settings.
Chemical Composition % of ASTM A182 F55 Super Duplex Steel WNFF Flange
Chemical Composition Limits |
Weight% | C | Mn | P | S | Si | Cr | Ni | Mo | N | W |
Super Duplex F55 | 0.03 max | 1.00 max | 0.03 max | 0.01 max | 1 max | 24-26 | 4.5-6.5 | 3-4 | 0.25 | 0.08-0.20 |
Mechanical properties of ASTM A182 F55 Super Duplex Steel WNFF Flange
Alloy | Tensile Strength N/mm² | Yield Strength 0.2% N/mm² | Elongation | Hardness HB |
Super Duplex F55 | 860 | 720 min | 16 min | 270 max |
Flanges are essential components in piping systems, and their face types—Flat Face (FF), Raised Face (RF), and Ring-Type Joint (RTJ)—are fundamental in determining their applications and sealing methods. Here’s an overview of each type, along with their differences and applications:
1. Flat Face (FF) Flange
- Description: The surface of the flange is flat, and it mates with a similar flat surface. No raised part is present.
- Applications:
- Commonly used in low-pressure systems or where there is a risk of pipe distortion due to thermal expansion.
- Often found in waterworks, sewage treatment plants, and certain chemical processing applications where tight sealing is required without excessive pressure.
2. Raised Face (RF) Flange
- Description: This flange has a raised area (the "face") around the bolt holes, which provides a larger sealing surface and better contact with the gasket.
- Applications:
- Widely used in high-pressure applications, including oil and gas pipelines, power generation (steam) systems, and chemical processing.
- RF flanges are more common than FF flanges due to their ability to maintain a better and more reliable seal under pressure.
3. Ring-Type Joint (RTJ) Flange
- Description: Features a groove at the flange face to accommodate a ring-shaped gasket. This design provides a metal-to-metal seal that is effective at high pressures and temperatures.
- Applications:
- Primarily used in high-pressure and high-temperature environments, such as those found in the oil and gas industries, refineries, and power plants.
- Suitable for critical applications where leakage must be eliminated.
Application
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Oil & Gas
- Offshore Platforms: Used in piping systems that require high corrosion resistance due to exposure to seawater and harsh environmental conditions.
- Pipelines: Essential for transporting oil and gas where strength and integrity are crucial, especially in deep-water or high-pressure scenarios.
- Subsea Equipment: Utilized in equipment that operates on the seabed, where protection against H₂S-containing media is vital for operational safety and longevity.
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Chemical Processing
- Reactors: Flanges are used to connect various vessels and components, ensuring a secure seal in chemical reactions.
- Heat Exchangers: Employed in systems that transfer heat efficiently while resisting corrosion from chemical exposure.
- Sulfuric Acid Handling Systems: The F55 material provides necessary resistance to highly corrosive environments.
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Desalination Plants
- High-Pressure Piping in Seawater Reverse Osmosis Systems: These flanges help in managing the high pressures required in desalination processes while resisting saltwater corrosion.
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Power Generation
- Flue Gas Desulfurization (FGD) Systems: Used in systems that scrub harmful sulfur compounds from flue gases, ensuring environmental compliance and efficiency.
- Cooling Water Circuits: Essential for maintaining the integrity of cooling systems that can be exposed to corrosive elements.
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