On April 25, 2025, an established client from China sent us an inquiry for ASTM A182 F904L weld neck flange. Both the material grade and the product type are common for us, so we quickly completed the quotation, and the client placed an order a week later.
ZIZI is a professional manufacturer specializing in the production and processing of pipes and pipe fittings. Our products are primarily used in industries such as chemical, petroleum, natural gas, water conservancy, power generation, and offshore engineering. Our product range includes various sizes of seamless pipes, welded pipes, butt-welding pipe fittings, high-pressure forged fittings, and flanges. We offer a wide range of materials, including carbon steel, stainless steel, alloy steel, low-temperature steel, duplex steel, and super alloys.
Purchase List
| ITEM | DESCRIPTION | QUANITITY | UNIT |
| 1 | WNRF DN100 Sch 10S, #150, ASTM A182 F-904L, FORGED ASME B 16.5 | 38 | EA |
| 2 | WNRF DN100 SCH10S PN10 ASTM A182 F-904L FORGED | 60 | EA |
Weld Neck Flange Inspection
Outer Diameter:
To ensure that the external dimensions of the flange meet the standard requirements, avoid interference with other components, and provide sufficient installation space for connecting bolts.
Thickness:
To ensure that the flange has sufficient strength and rigidity to withstand the design pressure load, prevent flange deformation or damage, and ensure the reliability and sealing of the connection.
Number of Bolt Holes:
To ensure that the number of bolt holes on the flange is consistent with that of the mating flange, which is a necessary condition for achieving flange connection. The number of bolt holes for a PN10 weld neck flange is 8.
Hub Diameter :
To ensure that the outer diameter of the flange neck (or spigot) matches the inner or outer diameter of the pipe to be welded.
ASTM A182 F904L Flange Chemical Composition
| CHEMICAL | LIMITS | C | Mn | P | S | Si | Ni | Cr | Mo | N | Ti | Cu |
| ASTM A182 F904L (N08904) | MIN | 23.00 | 19.00 | 4.00 | 1 | |||||||
| MAX | 0.02 | 2.00 | 0.040 | 0.030 | 1.00 | 28.00 | 23.00 | 5.00 | 0.10 | 2.00 |
ASTM A182 F904L Flange Mechanical Property
| MATERIAL | T.S (MPA) | Y.S (MPA) | EL % |
| ASTM A182 F904L | 490 min | 215 min | 35 min |
Specification of Weld Neck Flanges
| Sealing Face | RF, FF, FTJ |
| Size Range | 1/2” – 48” / DN15 – DN1200 |
| Pressure Rating | Class 150, 300, 600, 900, 1500, 2500lb |
| Standard | ASME / ANSI B16.5, ASME B16.47 Series A/B |
| Stainless Steel | ASTM A182 F304/304L/304H, 316/316L, 310S, 317,347,904L |
ASTM A182 is the standard specification for forged or rolled alloy and stainless steel pipe flanges, forged fittings, and valves and parts for high-temperature service.
“F” designation: In ASTM A182, “F” indicates that the material is a forging grade. This means the flanges are typically produced by hot forging, which results in a denser, more uniform grain structure and superior mechanical properties compared to cast flanges.
“904L” designation: This refers to the specific stainless steel grade, which is a highly alloyed austenitic stainless steel.
Advantages of ASTM A182 F904L Weld Neck Flanges
Robust Connection: The butt-weld connection provides a robust, leak-proof joint that can withstand severe service conditions, including high pressure and thermal cycling.
Superior Corrosion Resistance: The F904L material ensures the flange itself can withstand highly corrosive media, matching the performance of pipes made from the same alloy.
Enhanced Mechanical Properties: Forging process (as implied by A182 F) enhances the strength, ductility, and toughness of the flange.
Reduced Stress Concentration: The tapered hub design minimizes stress concentration at the base of the flange, making it ideal for critical applications.
Radiography Inspectable: The butt-weld connection allows for full radiographic inspection, ensuring the integrity of the weld.
Various Face Types: Commonly available with Raised Face (RF), Flat Face (FF), or Ring Type Joint (RTJ) faces, depending on sealing requirements.
Weld Neck Flange Dimensions
Stainless steel weld neck flanges are a common type of flange used in medium- to high-pressure piping systems. They offer excellent sealing performance and structural strength. By connecting to the pipe via butt welding, these flanges effectively reduce stress concentration, making them suitable for the transportation of high-temperature, high-pressure, and corrosive media.
The standard size range for stainless steel weld neck flanges is from 1/2 inch (DN15) to 24 inches (DN600), with larger sizes available for specific projects (e.g., sizes from 26″ to 60″ are covered under ASME B16.47). They are manufactured in accordance with ASME B16.5 standards and are available in various pressure ratings—such as Class 150, 300, 600, 900, 1500, and 2500—or PN ratings, including PN6, PN10, PN16, PN25, and PN40, to meet different operational requirements.
Class 150 Weld Neck Flange Dimension
ASTM A182 F904L Weld Neck Flange Applications
Offshore and marine piping
Chemical and petrochemical plants
Acid processing units
Desalination plants
Flue gas scrubbers
Heat exchangers and reactors
About Us
We are professional in manufacturing and exporting flanges in various materials.
