ASME B16.47 ASTM A182 ss904L WN flange supplier. Contact us to get free quote and sample!
The ASTM A182 ss904L WN flange is a forged stainless steel flange manufactured based on the ASTM A182/A182M standard. It is made of high-performance 904L stainless steel (UNS N08904,1.4539). "WN" stands for "welded neck," meaning a butt-welded flange with a tapered neck. This flange design is suitable for piping systems operating under high pressure, high temperature, or with severe temperature fluctuations. HT PIPE supply all different types and scales of flanges. Please feel free to contact us for further product information and pricing.
what is wn flange?
Flange: An annular, disc-shaped flange similar to other flange types, with bolt holes for bolting to the mating flange.
Tapered neck: This is the most distinctive feature of the WN flange. It is a tapered (or cylindrical) neck extending from the flange.
Butt weld groove: The end of the tapered neck has a specific groove angle (usually 37.5° with a blunt edge of approximately 3.2mm) to prepare for butt welding to the pipe.
ASTM A182 ss904L WN flange Corrosion Resistance
Uniform corrosion resistance: ASTM A182 ss904L WN flange exhibits excellent corrosion resistance in a wide range of sulfuric and phosphoric acids, as well as most organic acids. For example, in pure sulfuric acid within a concentration range of 0-98%, 904L can be used at temperatures up to 40°C, in pure phosphoric acid within a concentration range of 0-85%, its corrosion resistance is also very good.
Resistance to pitting and crevice corrosion: The high content of chromium, molybdenum, and nitrogen gives it a high pitting resistance equivalent (PREN), demonstrating superior pitting and crevice corrosion resistance compared to 316L and 317L in environments containing chloride ions (such as seawater, brine, and chemical process fluids).
Resistance to stress corrosion cracking: The high nickel content enhances the material's resistance to stress corrosion cracking in chloride solutions and hydrogen sulfide-rich environments.
Resistance to intergranular corrosion: The ultra-low carbon design and stabilized heat treatment make ASTM A182 ss904L WN flange insensitive to intergranular corrosion.
Why choose asme b16.47 WN flange?
s904L WN flange structural integrity and strength
Uniform stress distribution: The tapered neck structure provides a smooth transition zone, effectively dissipating stresses in the pipe (such as internal pressure, thermal stress, and external loads) from the pipe wall to the thicker flange. This design significantly reduces stress concentration at the flange-to-pipe connection, avoiding the risk of brittle fracture associated with right-angle connections.
High deformation resistance: The tapered neck provides additional rigidity and support when subjected to bending moments or alternating loads, making the connection less susceptible to bending or deformation.
904L WN flangeHigh connection reliability
Butt weld: 100% full penetration butt welds are used to connect to the pipe. This weld is typically stronger than the pipe base metal, ensuring the joint has the same mechanical strength and sealing properties as the pipe itself. It can be rigorously inspected for quality using non-destructive testing methods such as radiographic testing (RT) and ultrasonic testing (UT).
Sealing Performance: The robust structure prevents flange deformation under bolt tightening and internal pressure, ensuring uniform gasket stress and maintaining a long-term, stable seal.
uns n08904 flange Fatigue and Vibration Resistance
Due to their excellent resistance to stress concentration and overall strength, ASTM A182 ss904L WN flange offer longer service life and greater reliability than other flange types (such as socket weld and threaded flanges) in conditions subject to vibration, pressure fluctuations, or temperature cycling.
ASTM A182 ss904L flange Easy for Nondestructive Testing
The regular geometry of the butt weld facilitates nondestructive testing (NDT) such as radiographic and ultrasonic testing to verify internal weld quality and ensure the safety of critical pipelines.
