Views: 1 Author: Site Editor Publish Time: 2025-11-17 Origin: Site
SS316 welded neck flange has the advantages of high strength and high sealing performance, and is applied in industrial pipeline systems under high pressure, high temperature, and corrosive conditions.
Welded neck flange is a type of flange that is connected to a pipeline by welding. It has a neck design that can form a sturdy overall structure after welding with the pipeline, improving the pressure bearing capacity of the connecting parts.
SS316L weld neck flange is manufactured according to ASME B16.5 standard, and the overall structure consists of three parts:
Firstly, the neck shape is designed to be conical or cylindrical, with a length that meets standard requirements, and a smooth transition between the inner wall and the inner wall of the pipeline;
Secondly, the flange is designed in a circular flat plate shape with bolt holes on the surface. The number, diameter, and spacing of the holes meet the requirements of ASEM B16.5 standard to ensure a tight connection of the flanges;
Thirdly, the types of sealing surfaces typically include RF, FF, MFM, TG, etc.
In addition, the surface of SS316L welded flanges is required to be free of oxide scale, scratches, and impurities, and have a clean and uniform appearance.
High strength connection: The welding between the neck and the pipeline adopts full penetration welding technology, and the weld strength is not lower than that of the flange body and pipeline material.
Excellent sealing performance: By pre tightening the bolts, the flange sealing surface is tightly adhered to the gasket.The leakage rate is much lower than other types such as SO flanges.
Stress dispersion effect: The conical design of the neck can evenly transmit the pressure and temperature stress of the medium inside the pipeline to the flange and bolts.
Easy to maintain and repair: Compared to direct welding of pipeline connections, weld neck flanges are detachable through bolt connections.
SS316L Steel flanges follow strict international standards to ensure product performance and dimensional accuracy.
The production process, dimensional tolerances, pressure ratings, etc. of SS316L WN flanges are mainly carried out in accordance with ASME B16.5, with a size range of NPS 1/2 to NPS 24 (DN15 to DN600) and a pressure rating of Class150-2500.
The material standard for SS316L weld neck flanges follows ASTM A182/A182M, which is specifically designed for forging stainless steel fittings, flanges, valve components, and other products. SS316L corresponds to the F316L grade in the standard, which specifies the chemical composition, mechanical properties, heat treatment process, and quality inspection requirements of the material.
Chemical Composition
| CHEMICAL | LIMITS | C | Mn | P | S | Si | Ni | Cr | Mo | N |
| ASTM A182 F316L | MIN | 10.00 | 16.00 | 2.00 | ||||||
| MAX | 0.03 | 2.00 | 0.045 | 0.030 | 1.00 | 15.00 | 18.00 | 3.00 | 0.01 |
Mechanical Properties
| MATERIAL | T.S (MPA) | Y.S (MPA) | EL % | R/A % |
| ASTM A182 F316L | 485 min | 170 min | 30 min | 50 min |
The heat treatment process requires solid solution treatment to improve material properties.
The size and weight of SS316L WN flanges must strictly comply with ASME B16.5 or EN1092-1 standards. The parameters of different nominal diameters (DN) and pressure grades (Class/PN) have significant differences. The following are examples of key parameters for common specifications (taking ASME B16.5 as an example):
| Nominal Pipe Size | A | B | C | D | E | F | G | H | I | J | Weight | |
| inch | mm | mm | mm | mm | mm | mm | mm | mm | Holes | mm | mm | kg / piece |
| 1/2 | 21.30 | 88.90 | 15.70 | 11.20 | 47.80 | 21.30 | 30.20 | 35.00 | 4 | 15.70 | 60.45 | 0.48 |
| 3/4 | 26.70 | 98.60 | 20.80 | 12.70 | 52.30 | 26.70 | 38.10 | 42.90 | 4 | 15.70 | 69.85 | 0.71 |
| 1 | 33.40 | 108.0 | 26.70 | 14.20 | 55.60 | 33.50 | 49.30 | 50.80 | 4 | 15.70 | 79.25 | 1.01 |
| 11/4 | 42.20 | 117.3 | 35.10 | 15.70 | 57.15 | 42.20 | 58.70 | 63.50 | 4 | 15.70 | 88.90 | 1.33 |
| 11/2 | 48.30 | 127.0 | 40.90 | 17.50 | 62.00 | 48.30 | 65.00 | 73.15 | 4 | 15.70 | 98.60 | 1.72 |
| 2 | 60.30 | 152.4 | 52.60 | 19.10 | 63.50 | 60.45 | 77.70 | 91.90 | 4 | 19.10 | 120.7 | 2.58 |
| 21/2 | 73.00 | 177.8 | 62.70 | 22.40 | 69.85 | 73. 15 | 90.4 | 104.6 | 4 | 19.10 | 139.7 | 4.11 |
| 3 | 88.90 | 190.5 | 78.00 | 23.90 | 69.85 | 88.90 | 108.0 | 127.0 | 4 | 19.10 | 152.4 | 4.92 |
| 31/2 | 101.6 | 215.9 | 90.20 | 23.90 | 71.40 | 101.6 | 122.2 | 139.7 | 8 | 19.10 | 177.8 | 6.08 |
| 4 | 114.3 | 228.6 | 102.40 | 23.90 | 76.20 | 114.3 | 134.9 | 157.2 | 8 | 19.10 | 190.5 | 6.84 |
| 5 | 141.3 | 254.0 | 128.3 | 23.90 | 88.90 | 141.2 | 163.6 | 185.7 | 8 | 22.40 | 215.9 | 8.56 |
| 6 | 168.3 | 279.4 | 154.2 | 25.40 | 88.90 | 168.4 | 192.0 | 215.9 | 8 | 22.40 | 241.3 | 10.6 |
| 8 | 219.1 | 342.9 | 202.7 | 28.40 | 101.6 | 219.2 | 246.1 | 269.7 | 8 | 22.40 | 298.5 | 17.6 |
| 10 | 273.0 | 406.4 | 254.5 | 30.20 | 101.6 | 273.0 | 304.8 | 323.8 | 12 | 25.40 | 362.0 | 24.0 |
| 12 | 323.8 | 482.6 | 304.8 | 31.75 | 114.3 | 323.8 | 365.3 | 381.0 | 12 | 25.40 | 431.8 | 36.5 |
| 14 | 355.6 | 533.4 | To be specified by the Purchaser | 35.10 | 127.0 | 355.6 | 400.1 | 412.7 | 12 | 28.40 | 476.3 | 48.4 |
| 16 | 406.4 | 596.9 | 36.60 | 127.0 | 406.4 | 475.2 | 469.9 | 16 | 28.40 | 539.8 | 60.6 | |
| 18 | 457.2 | 635.0 | 39.60 | 139.7 | 457.2 | 505.0 | 533.4 | 16 | 31.75 | 577.9 | 68.3 | |
| 20 | 508.0 | 698.5 | 42.90 | 144.5 | 508.0 | 558.8 | 584.2 | 20 | 31.75 | 635.0 | 84.5 | |
| 24 | 609.6 | 812.8 | 47.80 | 152.4 | 609.6 | 663.4 | 692.1 | 20 | 35.10 | 749.3 | 115 | |
| Nominal Pipe Size | A | B | C | D | E | F | G | H | I | J | Weight | |
| inch | mm | mm | mm | mm | mm | mm | mm | mm | Holes | mm | mm | kg / piece |
| 1/2 | 21.30 | 95.20 | 15.70 | 14.20 | 52.30 | 21.30 | 38.10 | 35.00 | 4 | 15.70 | 66.55 | 0.75 |
| 3/4 | 26.70 | 117.3 | 20.80 | 15.70 | 57.15 | 26.70 | 47.70 | 42.90 | 4 | 19.00 | 82.50 | 1.26 |
| 1 | 33.40 | 123.9 | 26.70 | 17.50 | 62.00 | 33.50 | 53.80 | 50.80 | 4 | 19.00 | 88.90 | 1.52 |
| 1 1/4 | 42.20 | 133.3 | 35.10 | 19.00 | 65.00 | 42.20 | 63.50 | 63.50 | 4 | 19.00 | 98.50 | 2.03 |
| 1 1/2 | 48.30 | 155.4 | 40.90 | 20.60 | 68.30 | 48.30 | 69.85 | 73. 15 | 4 | 22.30 | 114.3 | 2.89 |
| 2 | 60.30 | 165. 1 | 52.60 | 22.30 | 69.85 | 60.45 | 84.00 | 91.90 | 8 | 19.00 | 127.0 | 3.4 |
| 2 1/2 | 73.00 | 190.5 | 62.70 | 25.40 | 76.20 | 73.15 | 100.0 | 104.6 | 8 | 22.30 | 149.3 | 5.17 |
| 3 | 88.90 | 209.5 | 78.00 | 28.40 | 79.25 | 88.90 | 117.3 | 127.0 | 8 | 22.30 | 168.1 | 6.93 |
| 3 1/2 | 101.6 | 228.6 | 90.20 | 30.20 | 81.00 | 101.6 | 133.3 | 139.7 | 8 | 22.30 | 184.1 | 8.67 |
| 4 | 114.3 | 254.0 | 102.4 | 31.70 | 85.80 | 114.3 | 146.0 | 157.2 | 8 | 22.30 | 200.1 | 11.2 |
| 5 | 141.3 | 279.4 | 128.3 | 35.00 | 98.50 | 141.2 | 177.8 | 185.7 | 8 | 22.30 | 234.9 | 15.1 |
| 6 | 168.3 | 317.5 | 154.2 | 36.50 | 98.50 | 168.4 | 206.2 | 215.9 | 12 | 22.30 | 269.7 | 19.1 |
| 8 | 219.1 | 381.0 | 202.7 | 41.10 | 111.2 | 219.2 | 260.3 | 269.7 | 12 | 25.40 | 330.2 | 29.9 |
| 10 | 273.0 | 444.5 | 254.5 | 47.70 | 117.3 | 273.0 | 320.5 | 323.8 | 16 | 28.40 | 387.3 | 42.7 |
| 12 | 323.8 | 520.7 | 304.8 | 50.80 | 130.0 | 323.8 | 374.6 | 381.0 | 16 | 31.70 | 450.8 | 61.8 |
| 14 | 355.6 | 584.2 | To be specified by the Purchaser | 53.80 | 142.7 | 355.6 | 425.4 | 412.7 | 20 | 31.70 | 514.3 | 85.8 |
| 16 | 406.4 | 647.7 | 57.15 | 146.0 | 406.4 | 482.6 | 469.9 | 20 | 35.00 | 571.5 | 106 | |
| 18 | 457.2 | 711.2 | 60.45 | 158.7 | 457.2 | 533.4 | 533.4 | 24 | 35.00 | 628.6 | 131 | |
| 20 | 508.0 | 774.7 | 63.50 | 162.0 | 508.0 | 587.2 | 584.2 | 24 | 35.00 | 685.8 | 158 | |
| 24 | 609.6 | 914.4 | 69.85 | 168.1 | 609.6 | 701.5 | 692.1 | 24 | 41.10 | 812.8 | 230 | |
| Nominal Pipe Size | A | B | C | D | E | F | G | H | I | J | Weight | |
| inch | mm | mm | mm | mm | mm | mm | mm | mm | Holes | mm | mm | kg / piece |
| 1/2 | 21.30 | 95.30 | To be specified by the Purchaser | 14.20 | 52.30 | 21.30 | 38.10 | 35.00 | 4 | 15.70 | 66.55 | 0.87 |
| 3/4 | 26.70 | 117.3 | 15.70 | 57.15 | 26.70 | 47.80 | 42.90 | 4 | 19.10 | 82.60 | 1.45 | |
| 1 | 33.40 | 124.0 | 17.50 | 62.00 | 33.50 | 53.80 | 50.80 | 4 | 19.10 | 88.90 | 1.76 | |
| 11/4 | 42.20 | 133.4 | 20.60 | 66.55 | 42.20 | 63.50 | 63.50 | 4 | 19.10 | 98.60 | 2.49 | |
| 11/2 | 48.30 | 155.4 | 22.40 | 69.85 | 48.30 | 69.85 | 73. 15 | 4 | 22.40 | 114.3 | 3.49 | |
| 2 | 60.30 | 165. 1 | 25.40 | 73.15 | 60.45 | 84.10 | 91.90 | 8 | 19.10 | 127.0 | 4.36 | |
| 21/2 | 73.00 | 190.5 | 28.40 | 79.25 | 73.15 | 100.1 | 104.6 | 8 | 22.40 | 149.4 | 6.43 | |
| 3 | 88.90 | 209.6 | 31.75 | 82.60 | 88.90 | 117.3 | 127.0 | 8 | 22.40 | 168.1 | 8.53 | |
| 31/2 | 101.6 | 228.6 | 35.10 | 85.90 | 101.6 | 133.4 | 139.7 | 8 | 25.40 | 184.2 | 10.7 | |
| 4 | 114.3 | 273. 1 | 38.10 | 101.6 | 114.3 | 152.4 | 157.2 | 8 | 25.40 | 215.9 | 17.4 | |
| 5 | 141.3 | 330.2 | 44.50 | 114.3 | 141.2 | 189.0 | 185.7 | 8 | 28.40 | 266.7 | 29.2 | |
| 6 | 168.3 | 355.6 | 47.80 | 117.3 | 168.4 | 222.3 | 215.9 | 12 | 28.40 | 292.1 | 34.9 | |
| 8 | 219.1 | 419. 1 | 55.60 | 133.4 | 219.2 | 273.1 | 269.7 | 12 | 31.75 | 349.3 | 53.9 | |
| 10 | 273.0 | 508.0 | 63.50 | 152.4 | 273.0 | 342.9 | 323.8 | 16 | 35.10 | 431.8 | 86.5 | |
| 12 | 323.8 | 558.8 | 66.55 | 155.4 | 323.8 | 400.1 | 381.0 | 20 | 35.10 | 489.0 | 103 | |
| 14 | 355.6 | 603.3 | 69.85 | 165.1 | 355.6 | 431.8 | 412.7 | 20 | 38.10 | 527.1 | 122 | |
| 16 | 406.4 | 685.8 | 76.20 | 177.8 | 406.4 | 495.3 | 469.9 | 20 | 41.10 | 603.3 | 170 | |
| 18 | 457.2 | 743.0 | 82.60 | 184.2 | 457.2 | 546.1 | 533.4 | 20 | 44.50 | 654.1 | 204 | |
| 20 | 508.0 | 812.8 | 88.90 | 190.5 | 508.0 | 609.6 | 584.2 | 24 | 44.50 | 723.9 | 254 | |
| 24 | 609.6 | 939.8 | 101.6 | 203.2 | 609.6 | 717.6 | 692.1 | 24 | 50.80 | 838.2 | 358 | |
| Nominal Pipe Size | A | B | C | D | E | F | G | H | I | J | Weight | |
| inch | mm | mm | mm | mm | mm | mm | mm | mm | Holes | mm | mm | kg / piece |
| 1/2 | 21.30 | 120.6 | To be specified by the Purchaser | 22.30 | 60.45 | 21.30 | 38.10 | 35.00 | 4 | 22.30 | 82.50 | 1.87 |
| 3/4 | 26.70 | 130.0 | 25.40 | 69.85 | 26.70 | 44.00 | 42.90 | 4 | 22.30 | 88.90 | 2.56 | |
| 1 | 33.40 | 149.3 | 28.40 | 73.15 | 33.50 | 52.30 | 50.80 | 4 | 25.40 | 101.6 | 3.74 | |
| 11/4 | 42.20 | 158.7 | 28.40 | 73.15 | 42.20 | 63.50 | 63.50 | 4 | 25.40 | 111.2 | 4.33 | |
| 11/2 | 48.30 | 177.8 | 31.70 | 82.50 | 48.30 | 69.85 | 73.15 | 4 | 28.40 | 123.9 | 5.94 | |
| 2 | 60.30 | 215.9 | 38.10 | 101.6 | 60.45 | 104.6 | 91.90 | 8 | 25.40 | 165.1 | 10.8 | |
| 21/2 | 73.00 | 244.3 | 41.10 | 104.6 | 73.15 | 123.9 | 104.6 | 8 | 28.40 | 190.5 | 15.0 | |
| 3 | 88.90 | 241.3 | 38.10 | 101.6 | 88.90 | 127.0 | 127.0 | 8 | 25.40 | 190.5 | 13.7 | |
| 4 | 114.3 | 292.1 | 44.40 | 114.3 | 114.3 | 158.7 | 157.2 | 8 | 31.70 | 234.9 | 22.5 | |
| 5 | 141.3 | 349.2 | 50.80 | 127.0 | 141.2 | 190.5 | 185.7 | 8 | 35.00 | 279.4 | 37.4 | |
| 6 | 168.3 | 381.0 | 55.60 | 139.7 | 168.4 | 234.9 | 215.9 | 12 | 31.70 | 317.5 | 47.7 | |
| 8 | 219. 1 | 469.9 | 63.50 | 162.0 | 219.2 | 298.4 | 269.7 | 12 | 38.10 | 393.7 | 81.3 | |
| 10 | 273.0 | 546.1 | 69.85 | 184. 1 | 273.0 | 368.3 | 323.8 | 16 | 38.10 | 469.9 | 119 | |
| 12 | 323.8 | 609.6 | 79.25 | 200. 1 | 323.8 | 419.1 | 381.0 | 20 | 38.10 | 533.4 | 157 | |
| 14 | 355.6 | 641.3 | 85.80 | 212.8 | 355.6 | 450.8 | 412.7 | 20 | 41.10 | 558.8 | 180 | |
| 16 | 406.4 | 704.8 | 88.90 | 215.9 | 406.4 | 508.0 | 469.9 | 20 | 44.40 | 615.9 | 217 | |
| 18 | 457.2 | 787.4 | 101.6 | 228.6 | 457.2 | 565.1 | 533.4 | 20 | 50.80 | 685.8 | 292 | |
| 20 | 508.0 | 857.2 | 107.9 | 247.6 | 508.0 | 622.3 | 584.2 | 20 | 53.80 | 749.3 | 362 | |
| 24 | 609.6 | 1041.4 | 139.7 | 292. 1 | 609.6 | 749.3 | 692.1 | 20 | 66.55 | 901.7 | 665 | |
| Nominal Pipe Size | A | B | C | D | E | F | G | H | I | J | Weight | |
| inch | mm | mm | mm | mm | mm | mm | mm | mm | Holes | mm | mm | kg / piece |
| 1/2 | 21.30 | 120.6 | To be specified by the Purchaser | 22.30 | 60.45 | 21.30 | 38.10 | 35.00 | 4 | 22.30 | 82.50 | 1.87 |
| 3/4 | 26.70 | 130.0 | 25.40 | 69.85 | 26.70 | 44.00 | 42.90 | 4 | 22.30 | 88.90 | 2.56 | |
| 1 | 33.40 | 149.3 | 28.40 | 73.15 | 33.50 | 52.30 | 50.80 | 4 | 25.40 | 101.6 | 3.74 | |
| 11/4 | 42.20 | 158.7 | 28.40 | 73.15 | 42.20 | 63.50 | 63.50 | 4 | 25.40 | 111.2 | 4.33 | |
| 11/2 | 48.30 | 177.8 | 31.70 | 82.50 | 48.30 | 69.85 | 73. 15 | 4 | 28.40 | 123.9 | 5.94 | |
| 2 | 60.30 | 215.9 | 38.10 | 101.6 | 60.45 | 104.6 | 91.90 | 8 | 25.40 | 165.1 | 10.8 | |
| 21/2 | 73.00 | 244.3 | 41.10 | 104.6 | 73.15 | 123.9 | 104.6 | 8 | 28.40 | 190.5 | 15.0 | |
| 3 | 88.90 | 266.7 | 47.70 | 177.3 | 88.9 | 133.3 | 127.0 | 8 | 31.70 | 203.2 | 19.9 | |
| 4 | 114.3 | 311.1 | 53.80 | 123.9 | 114.3 | 162.0 | 157.2 | 8 | 35.00 | 241.3 | 29.9 | |
| 5 | 141.3 | 374.6 | 73.15 | 155.4 | 141.2 | 196.8 | 185.7 | 8 | 41.10 | 292.1 | 55.4 | |
| 6 | 168.3 | 393.7 | 82.50 | 171.4 | 168.4 | 228.6 | 215.9 | 12 | 38.10 | 317.5 | 68.4 | |
| 8 | 219.1 | 482.6 | 91.90 | 212.8 | 219.2 | 292.1 | 269.7 | 12 | 44.40 | 393.7 | 117 | |
| 10 | 273.0 | 584.2 | 107.9 | 254.0 | 273.0 | 368.3 | 323.8 | 12 | 50.80 | 482.6 | 194 | |
| 12 | 323.8 | 673. 1 | 123.9 | 282.4 | 323.8 | 450.8 | 381.0 | 16 | 53.80 | 571.5 | 288 | |
| 14 | 355.6 | 749.3 | 133.3 | 298.4 | 355.6 | 495.3 | 412.7 | 16 | 60.45 | 635.0 | 380 | |
| 16 | 406.4 | 825.5 | 146.0 | 311. 1 | 406.4 | 552.4 | 469.9 | 16 | 66.55 | 704.8 | 485 | |
| 18 | 457.2 | 914.4 | 162.0 | 327.1 | 457.2 | 596.9 | 533.4 | 16 | 73.15 | 774.7 | 644 | |
| 20 | 508.0 | 984.2 | 177.8 | 355.6 | 508.0 | 641.3 | 584.2 | 16 | 79.25 | 831.8 | 775 | |
| 24 | 609.6 | 1168.4 | 203.2 | 406.4 | 609.6 | 762.0 | 692.1 | 16 | 91.90 | 990.6 | 1232 | |
| Nominal Pipe Size | A | B | C | D | E | F | G | H | I | J | Weight | |
| inch | mm | mm | mm | mm | mm | mm | mm | mm | Holes | mm | mm | kg / piece |
| 1/2 | 21.30 | 133.4 | To be specified by the Purchaser | 30.20 | 73. 15 | 21.30 | 42.90 | 35.00 | 4 | 22.40 | 88.90 | 3.12 |
| 3/4 | 26.70 | 139.7 | 31.75 | 79.25 | 26.70 | 50.80 | 42.90 | 4 | 22.40 | 95.30 | 3.70 | |
| 1 | 33.40 | 158.8 | 35.10 | 88.90 | 33.50 | 57.15 | 50.80 | 4 | 25.40 | 108.0 | 5.24 | |
| 11/4 | 42.20 | 184.2 | 38.10 | 95.30 | 42.20 | 73.15 | 63.50 | 4 | 28.40 | 130.0 | 7.74 | |
| 11/2 | 48.30 | 203.2 | 44.50 | 111.3 | 48.30 | 79.25 | 73.15 | 4 | 31.75 | 146. 1 | 10.9 | |
| 2 | 60.30 | 235.0 | 50.80 | 127.0 | 60.45 | 95.30 | 91.90 | 8 | 28.40 | 171.5 | 16.2 | |
| 21/2 | 73.00 | 266.7 | 57.15 | 142.7 | 73.15 | 114.3 | 104.6 | 8 | 31.75 | 196.9 | 23.7 | |
| 3 | 88.90 | 304.8 | 66.55 | 168.1 | 88.90 | 133.4 | 127.0 | 8 | 35.10 | 228.6 | 36.2 | |
| 4 | 114.3 | 355.6 | 76.20 | 190.5 | 114.3 | 165.1 | 157.2 | 8 | 41.10 | 273. 1 | 55.3 | |
| 5 | 141.3 | 419.1 | 91.90 | 228.6 | 141.2 | 203.2 | 185.7 | 8 | 47.80 | 323.9 | 92.5 | |
| 6 | 168.3 | 482.6 | 108 | 273.1 | 168.4 | 235.0 | 215.9 | 8 | 53.80 | 368.3 | 143 | |
| 8 | 219.1 | 552.5 | 127.0 | 317.5 | 219.2 | 304.8 | 269.7 | 12 | 53.80 | 438.2 | 215 | |
| 10 | 273.0 | 673.1 | 165.1 | 419.1 | 273.0 | 374.7 | 323.8 | 12 | 66.55 | 539.8 | 406 | |
| 12 | 323.8 | 762.0 | 184.2 | 463.6 | 323.8 | 441.5 | 381.0 | 12 | 73.15 | 619.3 | 572 | |
SS316L WN flanges have excellent performance advantages and are widely used in pipeline systems in multiple industrial fields.
Chemical and petrochemical industries.
Ocean Engineering
Medicine and food processing
Energy and Environmental Protection
Low temperature engineering
SS316L weld neck flanges strictly comply with international standards such as ASME B16.5 and ASTM A182 for production and quality control. They match size and performance parameters for different working conditions, and can meet the strict requirements of chemical, marine engineering, pharmaceutical, energy and other fields.
