Weld Neck Flange, commonly known as WN Flange, is a high-performance forged flange designed for high-pressure and high-temperature piping systems.
The term “Weld Neck” refers to the flange’s long tapered hub with increased wall thickness, while “Butt Weld” indicates the connection method where the beveled end of the flange neck is aligned with the pipe and joined by full penetration welding.
As one of the strongest and most reliable flange types used in pressure piping systems, the Weld Neck Flange provides excellent sealing performance, superior mechanical strength, and outstanding resistance to pressure and temperature stresses.
The connection area between the flange body and pipeline adopts a gradually tapered reinforced hub design, allowing stress to be evenly distributed and reducing stress concentration. This structure effectively prevents stress cracking and enables the flange to withstand.
The flange neck is machined with a standard welding bevel, allowing full penetration butt welding with seamless pipes. The weld strength is equivalent to the parent pipe material, ensuring excellent overall pressure-bearing capability and structural integrity.
Note: The flange inner diameter (B) is determined by the wall thickness of the steel pipe and shall be specified by the user at the time of ordering.（Unit: mm）
| DN | NPS | Type | Part No | A | D | K | L | Th | n | C | N | H | P | E | F |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 15 | 1/2 | WN-150LB-RF | XLXWN150RF05 | 21.3 | 90.0 | 60.3 | 16.0 | M14 | 4.0 | 9.6 | 15.5 | 46.0 | |||
| 20 | 3/4 | WN-150LB-RF | XLXWN150RF075 | 26.9 | 100.0 | 69.9 | 16.0 | M14 | 4.0 | 11.2 | 21.0 | 51.0 | |||
| 25 | 1 | WN-150LB-RF | XLXWN150RF1 | 33.7 | 110.0 | 79.4 | 16.0 | M14 | 4.0 | 12.7 | 27.0 | 54.0 | 47.6 | 6.4 | 8.7 |
| 32 | 1 1/4 | WN-150LB-RF | XLXWN150RF125 | 42.4 | 115.0 | 88.9 | 16.0 | M14 | 4.0 | 14.3 | 35.0 | 56.0 | 57.2 | 6.4 | 8.7 |
| 40 | 1 1/2 | WN-150LB-RF | XLXWN150RF15 | 48.3 | 125.0 | 98.4 | 16.0 | M14 | 4.0 | 15.9 | 41.0 | 60.0 | 65.1 | 6.4 | 8.7 |
| 50 | 2 | WN-150LB-RF | XLXWN150RF2 | 60.3 | 150.0 | 120.7 | 18.0 | M16 | 4.0 | 17.5 | 52.0 | 62.0 | 82.6 | 6.4 | 8.7 |
| 65 | 2 1/2 | WN-150LB-RF | XLXWN150RF25 | 76.1 | 180.0 | 139.7 | 18.0 | M16 | 4.0 | 20.7 | 66.0 | 68.0 | 101.6 | 6.4 | 8.7 |
| 80 | 3 | WN-150LB-RF | XLXWN150RF3 | 88.9 | 190.0 | 152.4 | 18.0 | M16 | 4.0 | 22.3 | 77.5 | 68.0 | 114.3 | 6.4 | 8.7 |
| 100 | 4 | WN-150LB-RF | XLXWN150RF4 | 114.3 | 230.0 | 190.5 | 18.0 | M16 | 8.0 | 22.3 | 101.5 | 75.0 | 149.2 | 6.4 | 8.7 |
| 125 | 5 | WN-150LB-RF | XLXWN150RF5 | 139.7 | 255.0 | 215.9 | 22.0 | M20 | 8.0 | 22.3 | 127.0 | 87.0 | 171.5 | 6.4 | 8.7 |
| 150 | 6 | WN-150LB-RF | XLXWN150RF6 | 168.3 | 280.0 | 241.3 | 22.0 | M20 | 8.0 | 23.9 | 154.0 | 87.0 | 193.7 | 6.4 | 8.7 |
| 200 | 8 | WN-150LB-RF | XLXWN150RF8 | 219.1 | 345.0 | 298.5 | 22.0 | M20 | 8.0 | 27.0 | 203.0 | 100.0 | 247.7 | 6.4 | 8.7 |
| 250 | 10 | WN-150LB-RF | XLXWN150RF10 | 273.0 | 405.0 | 362.0 | 26.0 | M24 | 12.0 | 28.6 | 255.0 | 100.0 | 304.8 | 6.4 | 8.7 |
| 300 | 12 | WN-150LB-RF | XLXWN150RF12 | 323.9 | 485.0 | 431.8 | 26.0 | M24 | 12.0 | 30.2 | 303.5 | 113.0 | 381.0 | 6.4 | 8.7 |
| 350 | 14 | WN-150LB-RF | XLXWN150RF14 | 355.6 | 535.0 | 476.3 | 30.0 | M27 | 12.0 | 33.4 | 125.0 | 396.9 | 6.4 | 8.7 | |
| 400 | 16 | WN-150LB-RF | XLXWN150RF16 | 406.4 | 595.0 | 539.8 | 30.0 | M27 | 16.0 | 35.0 | 125.0 | 454.0 | 6.4 | 8.7 | |
| 450 | 18 | WN-150LB-RF | XLXWN150RF18 | 457.0 | 635.0 | 577.9 | 33.0 | M30 | 16.0 | 38.1 | 138.0 | 517.5 | 6.4 | 8.7 | |
| 500 | 20 | WN-150LB-RF | XLXWN150RF20 | 508.0 | 700.0 | 635.0 | 33.0 | M30 | 20.0 | 41.3 | 143.0 | 558.8 | 6.4 | 8.7 | |
| 600 | 24 | WN-150LB-RF | XLXWN150RF24 | 610.0 | 815.0 | 749.3 | 36.0 | M33 | 20.0 | 46.1 | 151.0 | 673.1 | 6.4 | 8.7 |
RF (Raised Face): The most widely used facing type for general applications. Suitable for steam systems, water supply and drainage pipelines, and conventional chemical processing lines.
MFM (Male & Female Face): Designed to improve sealing reliability by preventing gasket extrusion under higher pressure conditions. Suitable for applications involving higher medium pressure and demanding sealing requirements.
RJ (Ring Type Joint Face): Designed for ultra-high pressure and critical service applications, such as oil & gas pipelines and high-pressure main piping systems in power plants. Combined with metallic ring gaskets, it provides excellent sealing performance and zero leakage reliability.
Manufactured by integral forging process to ensure high density and uniform mechanical properties.
Eliminates defects commonly found in cast products, such as porosity, shrinkage cavities, and internal looseness.
Provides superior strength, durability, and pressure resistance.
Manufactured in accordance with pressure equipment and pressure piping standards.
