Weld Neck Flanges
Certification standards
ASME B16.5
ISO 7005
INTRO
We Manufacture Stainless Steel Weld Neck Flange from Size 1/2 to 24 NPS, pressure classes from 150 to 2500. Low MoQ, Direct to Factory Price and available for custom bolt hole, size options. For more details, please refer to Table of Dimensions below, or ASK OUR ENGINEER for more assistance.
Standard:
GB/T9119-2010
HG/T20592-2009
HG/T20615-2009
DIN
ASME
BS
JIS
GB/T9119-2010
HG/T20592-2009
HG/T20615-2009
DIN
ASME
BS
JIS
Material:
304:F304 S30408 S30408II S30408III S30400
304L:S30403 S30403II 30403 30403II
316L:31603 31603II 31603III
2507(F53)
2205(F51)
TP310S(06Cr5Ni20)
TP321(06Cr18Ni11)
S22053III=2205III
T321-32168=321
Our Weld Neck Flanges are designed for high-pressure and high-temperature applications. Manufactured with precise tolerances and in compliance with ANSI, ASTM, DIN and JIS standards.
///Class 150///
| Nominal size | Steel Pipe outer diameter | Connection size | flange thickness | flange inner diameter | flange neck big end | flange height | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| DN | NPS | A | Flange outer diameter D | Central circle diameter K | Bolt hole diameter L | Number of bolt holes n | Bolt Th | C | B | N | H |
| 15 | 1/2 | 21.3 | 90 | 60.3 | 16 | 4 | M14 | 9.6 | 15.5 | 30 | 46 |
| 20 | 3/4 | 26.9 | 100 | 69.9 | 16 | 4 | M14 | 11.2 | 21 | 38 | 51 |
| 25 | 1 | 33.7 | 110 | 79.4 | 16 | 4 | M14 | 12.7 | 27 | 49 | 54 |
| 32 | 1 1/4 | 42.4 | 115 | 88.9 | 16 | 4 | M14 | 14.3 | 35 | 59 | 56 |
| 40 | 1 1/2 | 48.3 | 125 | 98.4 | 16 | 4 | M14 | 15.9 | 41 | 65 | 60 |
| 50 | 2 | 60.3 | 150 | 120.7 | 18 | 4 | M16 | 17.5 | 52 | 78 | 62 |
| 65 | 2 1/2 | 76.1 | 180 | 139.7 | 18 | 4 | M16 | 20.7 | 66 | 90 | 68 |
| 80 | 3 | 88.9 | 190 | 152.4 | 18 | 4 | M16 | 22.3 | 77.5 | 108 | 68 |
| 100 | 4 | 114.3 | 230 | 190.5 | 18 | 8 | M16 | 22.3 | 101.5 | 135 | 75 |
| 125 | 5 | 139.7 | 255 | 215.9 | 22 | 8 | M20 | 22.3 | 127 | 164 | 87 |
| 150 | 6 | 168.3 | 280 | 241.3 | 22 | 8 | M20 | 23.9 | 154 | 192 | 87 |
| 200 | 8 | 219.1 | 345 | 298.5 | 22 | 8 | M20 | 27 | 203 | 246 | 100 |
| 250 | 10 | 273 | 405 | 362 | 26 | 12 | M24 | 28.6 | 255 | 305 | 100 |
| 300 | 12 | 323.9 | 485 | 431.8 | 26 | 12 | M24 | 30.2 | 303.5 | 365 | 113 |
| 350 | 14 | 355.6 | 535 | 476.3 | 30 | 12 | M27 | 33.4 | &/8211; | 400 | 125 |
| 400 | 16 | 406.4 | 595 | 539.8 | 30 | 16 | M27 | 35 | &/8211; | 457 | 125 |
| 450 | 18 | 457 | 635 | 577.9 | 33 | 16 | M30 | 38.1 | &/8211; | 505 | 138 |
| 500 | 20 | 508 | 700 | 635 | 33 | 20 | M30 | 41.3 | &/8211; | 559 | 143 |
| 600 | 24 | 610 | 815 | 749.3 | 36 | 20 | M33 | 46.1 | &/8211; | 663 | 151 |
///Class 300///
| Nominal size | Steel Pipe outer diameter | Connection size | flange thickness | flange inner diameter | flange neck big end | flange height | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| DN | NPS | A | Flange outer diameter D | Central circle diameter K | Bolt hole diameter L | Number of bolt holes n | Bolt Th | C | B | N | H |
| 15 | 1/2 | 21.3 | 95 | 66.7 | 16 | 4 | M14 | 12.7 | 15.5 | 38 | 51 |
| 20 | 3/4 | 26.9 | 115 | 82.6 | 18 | 4 | M16 | 14.3 | 21 | 48 | 56 |
| 25 | 1 | 33.7 | 125 | 88.9 | 18 | 4 | M16 | 15.9 | 27 | 54 | 60 |
| 32 | 1 1/4 | 42.4 | 135 | 98.4 | 18 | 4 | M16 | 17.5 | 35 | 64 | 64 |
| 40 | 1 1/2 | 48.3 | 155 | 114.3 | 22 | 4 | M20 | 19.1 | 41 | 70 | 67 |
| 50 | 2 | 60.3 | 165 | 127 | 18 | 8 | M16 | 20.7 | 52 | 84 | 68 |
| 65 | 2 1/2 | 76.1 | 190 | 149.2 | 22 | 8 | M20 | 23.9 | 66 | 100 | 75 |
| 80 | 3 | 88.9 | 210 | 168.3 | 22 | 8 | M20 | 27 | 77.5 | 117 | 78 |
| 100 | 4 | 114.3 | 255 | 200 | 22 | 8 | M20 | 30.2 | 101.5 | 146 | 84 |
| 125 | 5 | 139.7 | 280 | 235 | 22 | 8 | M20 | 33.4 | 127 | 178 | 97 |
| 150 | 6 | 168.3 | 320 | 269.9 | 22 | 12 | M20 | 35 | 154 | 206 | 97 |
| 200 | 8 | 219.1 | 380 | 330.2 | 26 | 12 | M24 | 39.7 | 203 | 260 | 110 |
| 250 | 10 | 273 | 445 | 387.4 | 30 | 16 | M27 | 46.1 | 255 | 321 | 116 |
| 300 | 12 | 323.9 | 520 | 450.8 | 33 | 16 | M30 | 49.3 | 303.5 | 375 | 129 |
| 350 | 14 | 355.6 | 585 | 514.4 | 33 | 20 | M30 | 52.4 | &/8211; | 425 | 141 |
| 400 | 16 | 406.4 | 650 | 571.5 | 36 | 20 | M33 | 55.6 | &/8211; | 483 | 144 |
| 450 | 18 | 457 | 710 | 628.6 | 36 | 24 | M33 | 58.8 | &/8211; | 533 | 157 |
| 500 | 20 | 508 | 775 | 685.8 | 36 | 24 | M33 | 62 | &/8211; | 587 | 160 |
| 600 | 24 | 610 | 915 | 812.8 | 42 | 24 | M39X3 | 68.3 | &/8211; | 702 | 167 |
///Class 600///
| Nominal size | Steel Pipe outer diameter | Connection size | flange thickness | flange inner diameter | flange neck big end | flange height | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| DN | NPS | A | Flange outer diameter D | Central circle diameter K | Bolt hole diameter L | Number of bolt holes n | Bolt Th | C | B | N | H |
| 15 | 1/2 | 21.3 | 95 | 66.7 | 16 | 4 | M14 | 14.3 | &/8211; | 38 | 52 |
| 20 | 3/4 | 26.9 | 115 | 82.6 | 18 | 4 | M16 | 15.9 | &/8211; | 48 | 57 |
| 25 | 1 | 33.7 | 125 | 88.9 | 18 | 4 | M16 | 17.5 | &/8211; | 54 | 62 |
| 32 | 1 1/4 | 42.4 | 135 | 98.4 | 18 | 4 | M16 | 20.7 | &/8211; | 64 | 67 |
| 40 | 1 1/2 | 48.3 | 155 | 114.3 | 22 | 4 | M20 | 22.3 | &/8211; | 70 | 70 |
| 50 | 2 | 60.3 | 165 | 127 | 18 | 8 | M16 | 25.4 | &/8211; | 84 | 73 |
| 65 | 2 1/2 | 76.1 | 190 | 149.2 | 22 | 8 | M20 | 28.6 | &/8211; | 100 | 79 |
| 80 | 3 | 88.9 | 210 | 168.3 | 22 | 8 | M20 | 31.8 | &/8211; | 117 | 83 |
| 100 | 4 | 114.3 | 275 | 215.9 | 26 | 8 | M24 | 38.1 | &/8211; | 152 | 102 |
| 125 | 5 | 139.7 | 330 | 266.7 | 30 | 8 | M27 | 44.5 | &/8211; | 189 | 114 |
| 150 | 6 | 168.3 | 355 | 292.1 | 30 | 12 | M27 | 47.7 | &/8211; | 222 | 117 |
| 200 | 8 | 219.1 | 420 | 349.2 | 33 | 12 | M30 | 55.6 | &/8211; | 273 | 133 |
| 250 | 10 | 273 | 510 | 431.8 | 36 | 16 | M33 | 63.5 | &/8211; | 343 | 152 |
| 300 | 12 | 323.9 | 560 | 489 | 36 | 20 | M33 | 66.7 | &/8211; | 400 | 156 |
| 350 | 14 | 355.6 | 605 | 527 | 39 | 20 | M36X3 | 69.9 | &/8211; | 432 | 165 |
| 400 | 16 | 406.4 | 685 | 603.2 | 42 | 20 | M39X3 | 76.2 | &/8211; | 495 | 178 |
| 450 | 18 | 457 | 745 | 654 | 45 | 20 | M42X3 | 82.6 | &/8211; | 546 | 184 |
| 500 | 20 | 508 | 815 | 723.9 | 45 | 24 | M42X3 | 88.9 | &/8211; | 610 | 190 |
| 600 | 24 | 610 | 940 | 838.2 | 51 | 24 | M48X3 | 101.6 | &/8211; | 718 | 203 |
///Class 900///
| Nominal size | Steel Pipe outer diameter | Connection size | flange thickness | flange inner diameter | flange neck big end | flange height | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| DN | NPS | A | Flange outer diameter D | Central circle diameter K | Bolt hole diameter L | Number of bolt holes n | Bolt Th | C | B | N | H |
| 15 | 1/2 | 21.3 | 120 | 82.6 | 22 | 4 | M20 | 22.3 | &/8211; | 38 | 60 |
| 20 | 3/4 | 26.9 | 130 | 88.9 | 22 | 4 | M20 | 25.4 | &/8211; | 44 | 70 |
| 25 | 1 | 33.7 | 150 | 101.6 | 26 | 4 | M24 | 28.6 | &/8211; | 52 | 73 |
| 32 | 1 1/4 | 42.4 | 160 | 111.1 | 26 | 4 | M24 | 28.6 | &/8211; | 64 | 73 |
| 40 | 1 1/2 | 48.3 | 180 | 123.8 | 30 | 4 | M27 | 31.8 | &/8211; | 70 | 83 |
| 50 | 2 | 60.3 | 215 | 165.1 | 26 | 8 | M24 | 38.1 | &/8211; | 105 | 102 |
| 65 | 2 1/2 | 76.1 | 245 | 190.5 | 30 | 8 | M27 | 41.3 | &/8211; | 124 | 105 |
| 80 | 3 | 88.9 | 240 | 190.5 | 26 | 8 | M24 | 38.1 | &/8211; | 127 | 102 |
| 100 | 4 | 114.3 | 290 | 235 | 33 | 8 | M30 | 44.5 | &/8211; | 159 | 114 |
| 125 | 5 | 139.7 | 350 | 279.4 | 36 | 8 | M33 | 50.8 | &/8211; | 190 | 127 |
| 150 | 6 | 168.3 | 380 | 317.5 | 33 | 12 | M30 | 55.6 | &/8211; | 235 | 140 |
| 200 | 8 | 219.1 | 470 | 393.7 | 39 | 12 | M36X3 | 63.5 | &/8211; | 298 | 162 |
| 250 | 10 | 273 | 545 | 469.9 | 39 | 16 | M36X3 | 69.9 | &/8211; | 368 | 184 |
| 300 | 12 | 323.9 | 610 | 533.4 | 39 | 20 | M36X3 | 79.4 | &/8211; | 419 | 200 |
| 350 | 14 | 355.6 | 640 | 558.8 | 42 | 20 | M39X3 | 85.8 | &/8211; | 451 | 213 |
| 400 | 16 | 406.4 | 705 | 616 | 45 | 20 | M42X3 | 88.9 | &/8211; | 508 | 216 |
| 450 | 18 | 457 | 785 | 685.8 | 51 | 20 | M48X3 | 101.6 | &/8211; | 565 | 229 |
| 500 | 20 | 508 | 855 | 749.3 | 55 | 20 | M52X3 | 108 | &/8211; | 622 | 248 |
| 600 | 24 | 610 | 1040 | 901.7 | 68 | 20 | M64X3 | 139.7 | &/8211; | 749 | 292 |
///Class 1500///
| Nominal size | Steel Pipe outer diameter | Connection size | flange thickness | flange inner diameter | flange neck big end | flange height | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| DN | NPS | A | Flange outer diameter D | Central circle diameter K | Bolt hole diameter L | Number of bolt holes n | Bolt Th | C | B | N | H |
| 15 | 1/2 | 21.3 | 120 | 82.6 | 22 | 4 | M20 | 22.3 | &/8211; | 38 | 60 |
| 20 | 3/4 | 26.9 | 130 | 88.9 | 22 | 4 | M20 | 25.4 | &/8211; | 44 | 70 |
| 25 | 1 | 33.7 | 150 | 101.6 | 26 | 4 | M24 | 28.6 | &/8211; | 52 | 73 |
| 32 | 1 1/4 | 42.4 | 160 | 111.1 | 26 | 4 | M24 | 28.6 | &/8211; | 64 | 73 |
| 40 | 1 1/2 | 48.3 | 180 | 123.8 | 30 | 4 | M27 | 31.8 | &/8211; | 70 | 83 |
| 50 | 2 | 60.3 | 215 | 165.1 | 26 | 8 | M24 | 38.1 | &/8211; | 105 | 102 |
| 65 | 2 1/2 | 76.1 | 245 | 190.5 | 30 | 8 | M27 | 41.3 | &/8211; | 124 | 105 |
| 80 | 3 | 88.9 | 265 | 203.2 | 33 | 8 | M30 | 47.7 | &/8211; | 133 | 117 |
| 100 | 4 | 114.3 | 310 | 241.3 | 36 | 8 | M33 | 54 | &/8211; | 162 | 124 |
| 125 | 5 | 139.7 | 375 | 292.1 | 42 | 8 | M39X3 | 73.1 | &/8211; | 197 | 156 |
| 150 | 6 | 168.3 | 395 | 317.5 | 39 | 12 | M36X3 | 82.6 | &/8211; | 229 | 171 |
| 200 | 8 | 219.1 | 485 | 393.7 | 45 | 12 | M42X3 | 92.1 | &/8211; | 292 | 213 |
| 250 | 10 | 273 | 585 | 482.6 | 51 | 12 | M48X3 | 108 | &/8211; | 368 | 254 |
| 300 | 12 | 323.9 | 675 | 571.5 | 55 | 16 | M52X3 | 123.9 | &/8211; | 451 | 283 |
| 350 | 14 | 355.6 | 750 | 635 | 60 | 16 | M56X3 | 133.4 | &/8211; | 495 | 298 |
| 400 | 16 | 406.4 | 825 | 704.8 | 68 | 16 | M64X3 | 146.1 | &/8211; | 552 | 311 |
| 450 | 18 | 457 | 915 | 774.7 | 74 | 16 | M70X3 | 162 | &/8211; | 597 | 327 |
| 500 | 20 | 508 | 985 | 831.8 | 80 | 16 | M76X3 | 177.8 | &/8211; | 641 | 356 |
| 600 | 24 | 610 | 1170 | 990.6 | 94 | 16 | M90X3 | 203.2 | &/8211; | 762 | 406 |
///Class 2500///
| Nominal size | Steel Pipe outer diameter | Connection size | flange thickness | flange inner diameter | flange neck big end | flange height | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| DN | NPS | A | Flange outer diameter D | Central circle diameter K | Bolt hole diameter L | Number of bolt holes n | Bolt Th | C | B | N | H |
| 15 | 1/2 | 21.3 | 135 | 88.9 | 22 | 4 | M20 | 30.2 | &/8211; | 43 | 73 |
| 20 | 3/4 | 26.9 | 140 | 95.2 | 22 | 4 | M20 | 31.8 | &/8211; | 51 | 79 |
| 25 | 1 | 33.7 | 160 | 108 | 26 | 4 | M24 | 35 | &/8211; | 57 | 89 |
| 32 | 1 1/4 | 42.4 | 185 | 130.2 | 30 | 4 | M27 | 38.1 | &/8211; | 73 | 95 |
| 40 | 1 1/2 | 48.3 | 205 | 146 | 33 | 4 | M30 | 44.5 | &/8211; | 79 | 111 |
| 50 | 2 | 60.3 | 235 | 171.4 | 30 | 8 | M27 | 50.9 | &/8211; | 95 | 127 |
| 65 | 21/2 | 76.1 | 265 | 196.8 | 33 | 8 | M30 | 57.2 | &/8211; | 114 | 143 |
| 80 | 3 | 88.9 | 305 | 228.6 | 36 | 8 | M33 | 66.7 | &/8211; | 133 | 168 |
| 100 | 4 | 114.3 | 355 | 273 | 42 | 8 | M39X3 | 76.2 | &/8211; | 165 | 190 |
| 125 | 5 | 139.7 | 420 | 323.8 | 48 | 8 | M45X3 | 92.1 | &/8211; | 203 | 229 |
| 150 | 6 | 168.3 | 485 | 368.3 | 55 | 8 | M52X3 | 108 | &/8211; | 235 | 273 |
| 200 | 8 | 219.1 | 550 | 438.2 | 55 | 12 | M52X3 | 127 | &/8211; | 305 | 318 |
| 250 | 10 | 273 | 675 | 539.8 | 68 | 12 | M64X3 | 165.1 | &/8211; | 375 | 419 |
| 300 | 12 | 323.9 | 760 | 619.1 | 74 | 12 | M70X3 | 184.2 | &/8211; | 441 | 464 |


