High-Quality Forged Stainless Steel Flanges & Pipe Fittings
WE PRODUCE FORGED FLANGES -- Your Reliable Industrial Pipeline Partner

Nominal Size | Outer Diameter | Inner Diameter | Flange Ring Height | Hub Diameter at Base | Weld End OD | Flange wall thickness | Sealing Face Diameter | Sealing Face Height | Flange Overall Height | Central circle diameter | Number of Bolt Holes | Bolt Hole Diameter |
DN | NPS | A | B | C | F | E |
| G |
| D | J |
| I |
15 | 1/2 | 120.6
| 15.7 | 22.3 | 38.1 | 21.3 | 5.6 | 35 | 6.4 | 60.45 | 82.6 | 4 | 22.3 |
20 | 3/4 | 130 | 20.8 | 25.4 | 44 | 26.7 | 5.9 | 42.9 | 6.4 | 69.85 | 88.9 | 4 | 22.3 |
25 | 1 | 149.3 | 26.7 | 28.4 | 52.3 | 33.5 | 6.8 | 50.8 | 6.4 | 73.15 | 101.6 | 4 | 25.4 |
32 | 1-1/4 | 158.7 | 35.1 | 28.4 | 63.5 | 42.2 | 7.1 | 63.5 | 6.4 | 73.15 | 111.3 | 4 | 25.4 |
40 | 1-1/2 | 177.8 | 40.9 | 31.7 | 69.85 | 48.3 | 7.4 | 73.15 | 6.4 | 82.5 | 124 | 4 | 28.4 |
50 | 2 | 215.9 | 52.6 | 38.1 | 104.6 | 60.45 | 7.9 | 91.9 | 6.4 | 101.6 | 165.1 | 8 | 25.4 |
65 | 2-1/2 | 244.3 | 62.7 | 41.1 | 123.9 | 73.15 | 10.5 | 104.6 | 6.4 | 104.6 | 190.5 | 8 | 28.4 |
80 | 3 | 266.7 | 78 | 47.7 | 133.3 | 88.9 | 10.9 | 127 | 6.4 | 177.3 | 203.2 | 8 | 31.7 |
100 | 4
| 311.1 | 102.4 | 53.8 | 162 | 114.3 | 11.9 | 157 | 6.4 | 123.9 | 241.3 | 8 | 35 |
125 | 5 | 374.6 | 128.3 | 73.15 | 196.8 | 141.2 | 12.9 | 185.7 | 6.4 | 155.4 | 292.1 | 8 | 41.1 |
150 | 6 | 393.7 | 154.2 | 82.5 | 228.6 | 168.4 | 14.2 | 215.9 | 6.4 | 171.4 | 317.5 | 12 | 38.1 |
200 | 8 | 482.6 | 202.7 | 91.9 | 292.1 | 219.2 | 16.5 | 269.7 | 6.4 | 212.8 | 393.7 | 12 | 44.4 |
250 | 10 | 584.2 | 254.5 | 107.9 | 368.3 | 273 | 18.5 | 323.8 | 6.4 | 254 | 482.6 | 12 | 50.8 |
300 | 12 | 673.1 | 304.8 | 123.9 | 450.8 | 323.8 | 19 | 381 | 6.4 | 282.4 | 571.5 | 16 | 53.8 |
350 | 14 | 749.3 | 336.6 | 133.3 | 495.3 | 355.6 | 19 | 412.7 | 6.4 | 298.4 | 635 | 16 | 60.5 |
400 | 16 | 825.5 | 387.4 | 146 | 552.4 | 406.4 | 19 | 469.9 | 6.4 | 311.1 | 704.8 | 16 | 66.6 |
450 | 18 | 914.4 | 438.2 | 162 | 569.9 | 457.2 | 19 | 533.4 | 6.4 | 327.1 | 774.7 | 16 | 73.2 |
500 | 20 | 984.2 | 489 | 177.8 | 641.3 | 508 | 19 | 584.2 | 6.4 | 355.6 | 831.8 | 16 | 79.3 |
600 | 24 | 1168.4 | 590.6 | 203.2 | 762 | 609.6 | 19 | 692.1 | 6.4 | 406.4 | 990.6 | 16 | 91.9 |
Structural Design Features
(1) Extended and Thickened Neck Structure
Neck Length: 30% - 50% longer than Class 600 LB WN flange, significantly reducing the stress concentration factor (≤1.2). Wall Thickness Enhancement: The neck thickness is increased according to ASME B16.5 standard. The neck thickness of DN100 flange can reach 45mm (only 28mm for 600 LB).
Transition Arc: A large - radius arc transition (R≥20mm) is adopted at the connection between the neck and the flange plate to avoid stress mutation.
(2) High - Precision Sealing Surface
Ring - Joint Face (RTJ) Standard Configuration:
An octagonal groove is used, matching R - type or RX - type metal ring gaskets.
The surface roughness of the sealing surface Ra≤1.6μm (mirror - level machining).
Raised Face (RF) Optional: Only used for non - critical liquid media, and needs to be matched with high - pressure spiral - wound gaskets (such as 316L + flexible graphite).