| NPS | O | tf | tf(lap) | X | Ah | Y(THD/ SO/SW) | Y (LAP) | Y (WN) | T | B (SO) | B (LAP) | B (WN) | r | D | Bolt Circle Dia. | Bolt Qty | Bolt Hole Dia. | Bolt Dia. |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1/2 | 89 | 9.7 | 11.2 | 30 | 21.3 | 14 | 16 | 46 | 16 | 22.4 | 22.9 | 15.7 | 3 | 10 | 60.5 | 4 | 5/8 | 1/2 |
| 3/4 | 99 | 11.2 | 12.7 | 38 | 26.7 | 14 | 16 | 51 | 16 | 27.7 | 28.2 | 20.8 | 3 | 11 | 69.8 | 4 | 5/8 | 1/2 |
| 1 | 108 | 12.7 | 14.2 | 49 | 33.5 | 16 | 18 | 54 | 18 | 34.5 | 35.1 | 26.7 | 3 | 13 | 79.2 | 4 | 5/8 | 1/2 |
| 1 1/4 | 117 | 14.2 | 15.7 | 59 | 42.2 | 19 | 21 | 56 | 21 | 43.2 | 43.7 | 35.1 | 5 | 14 | 88.9 | 4 | 5/8 | 1/2 |
| 1 1/2 | 127 | 15.9 | 17.5 | 65 | 48.3 | 21 | 22 | 60 | 22 | 49.5 | 50 | 40.9 | 6 | 16 | 98.6 | 4 | 5/8 | 1/2 |
| 2 | 152 | 17.5 | 19 | 78 | 60.5 | 24 | 25 | 62 | 25 | 61.9 | 62.5 | 52.6 | 8 | 18 | 120.6 | 4 | 3/4 | 5/8 |
| 2 1/2 | 178 | 20.6 | 22.4 | 90 | 73.2 | 27 | 28 | 68 | 28 | 74.7 | 75.4 | 62.7 | 8 | 19 | 139.7 | 4 | 3/4 | 5/8 |
| 3 | 190 | 22.4 | 23.9 | 108 | 88.9 | 28 | 30 | 68 | 30 | 90.7 | 91.4 | 78 | 10 | 21 | 152.4 | 4 | 3/4 | 5/8 |
| 3 1/2 | 216 | 22.4 | 23.9 | 122 | 101.6 | 30 | 32 | 70 | 32 | 103.4 | 104.1 | 90.2 | 10 | 177.8 | 8 | 3/4 | 5/8 | |
| 4 | 229 | 22.4 | 23.9 | 135 | 114.3 | 32 | 33 | 75 | 33 | 116.1 | 116.8 | 102.4 | 11 | 190.5 | 8 | 3/4 | 5/8 | |
| 5 | 254 | 22.4 | 23.9 | 164 | 141.2 | 35 | 37 | 87 | 37 | 143.8 | 144.5 | 128.3 | 11 | 215.9 | 8 | 7/8 | 3/4 | |
| 6 | 279 | 23.9 | 25.4 | 192 | 168.4 | 38 | 40 | 87 | 40 | 170.7 | 171.4 | 154.2 | 13 | 241.3 | 8 | 7/8 | 3/4 | |
| 8 | 343 | 26.9 | 28.4 | 246 | 219.2 | 43 | 44 | 100 | 44 | 221.5 | 222.2 | 202.7 | 13 | 298.4 | 8 | 7/8 | 3/4 | |
| 10 | 406 | 28.4 | 30.2 | 305 | 273 | 48 | 49 | 100 | 49 | 276.4 | 277.4 | 254.5 | 13 | 362 | 12 | 1 | 7/8 | |
| 12 | 483 | 30.2 | 31.8 | 365 | 323.8 | 54 | 56 | 113 | 56 | 327.2 | 328.2 | 304.8 | 13 | 431.8 | 12 | 1 | 7/8 | |
| 14 | 553 | 33.3 | 35.1 | 400 | 355.6 | 56 | 79 | 125 | 57 | 359.2 | 360.2 | 13 | 476.2 | 12 | 1 1/8 | 1 | ||
| 16 | 597 | 35.1 | 36.6 | 457 | 406.4 | 62 | 87 | 125 | 64 | 410.5 | 411.2 | 13 | 539.9 | 16 | 1 1/8 | 1 | ||
| 18 | 635 | 38.1 | 39.6 | 505 | 457.2 | 67 | 97 | 138 | 68 | 461.8 | 462.3 | 13 | 577.8 | 16 | 1 1/4 | 1 1/8 | ||
| 20 | 698 | 41.1 | 42.9 | 559 | 508 | 71 | 103 | 143 | 73 | 513.1 | 514.4 | 13 | 635 | 20 | 1 1/4 | 1 1/8 | ||
| 22 | 749 | 44.4 | 46 | 610 | 558.8 | 78 | 108 | 148 | 564.4 | 565.2 | 13 | 692.2 | 20 | 1 3/8 | 1 1/4 | |||
| 24 | 813 | 46 | 47.8 | 663 | 609.6 | 81 | 111 | 151 | 83 | 616 | 616 | 13 | 749.3 | 20 | 1 3/8 | 1 1/4 |
| NPS | O | tf | tf(lap) | X | Ah | Y(THD/ SO/SW) | Y (LAP) | Y (WN) | T | B (SO) | B (LAP) | B (WN) | r | D | Bolt Circle Dia. | Bolt Qty | Bolt Hole Dia. | Bolt Dia. |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1/2 | 3.5 | 0.38 | 0.44 | 1.19 | 0.84 | 0.56 | 0.62 | 1.81 | 0.62 | 0.88 | 0.9 | 0.62 | 0.12 | 0.38 | 2.38 | 4 | 5/8 | 1/2 |
| 3/4 | 3.88 | 0.44 | 0.5 | 1.5 | 1.05 | 0.56 | 0.62 | 2 | 0.62 | 1.09 | 1.11 | 0.82 | 0.12 | 0.44 | 2.75 | 4 | 5/8 | 1/2 |
| 1 | 4.25 | 0.5 | 0.56 | 1.94 | 1.32 | 0.62 | 0.69 | 2.12 | 0.69 | 1.36 | 1.38 | 1.05 | 0.12 | 0.5 | 3.12 | 4 | 5/8 | 1/2 |
| 1 1/4 | 4.62 | 0.56 | 0.62 | 2.31 | 1.66 | 0.75 | 0.81 | 2.19 | 0.81 | 1.7 | 1.72 | 1.38 | 0.19 | 0.56 | 3.50 | 4 | 5/8 | 1/2 |
| 1 1/2 | 5 | 0.62 | 0.69 | 2.56 | 1.9 | 0.81 | 0.88 | 2.38 | 0.88 | 1.95 | 1.97 | 1.61 | 0.25 | 0.62 | 3.88 | 4 | 5/8 | 1/2 |
| 2 | 6 | 0.69 | 0.75 | 3.06 | 2.38 | 0.94 | 1 | 2.44 | 1 | 2.44 | 2.46 | 2.07 | 0.31 | 0.69 | 4.75 | 4 | 3/4 | 5/8 |
| 2 1/2 | 7 | 0.81 | 0.88 | 3.56 | 2.88 | 1.06 | 1.12 | 2.69 | 1.12 | 2.94 | 2.97 | 2.47 | 0.31 | 0.75 | 5.50 | 4 | 3/4 | 5/8 |
| 3 | 7.5 | 0.88 | 0.94 | 4.25 | 3.5 | 1.12 | 1.19 | 2.69 | 1.19 | 3.57 | 3.6 | 3.07 | 0.38 | 0.81 | 6.00 | 4 | 3/4 | 5/8 |
| 3 1/2 | 8.5 | 0.88 | 0.94 | 4.81 | 4 | 1.19 | 1.25 | 2.75 | 1.25 | 4.07 | 4.1 | 3.55 | 0.38 | 7.00 | 8 | 3/4 | 5/8 | |
| 4 | 9 | 0.88 | 0.94 | 5.31 | 4.5 | 1.25 | 1.31 | 2.94 | 1.31 | 4.57 | 4.6 | 4.03 | 0.44 | 7.50 | 8 | 3/4 | 5/8 | |
| 5 | 10 | 0.88 | 0.94 | 6.44 | 5.56 | 1.38 | 1.44 | 3.44 | 1.44 | 5.66 | 5.69 | 5.05 | 0.44 | 8.50 | 8 | 7/8 | 3/4 | |
| 6 | 11 | 0.94 | 1 | 7.56 | 6.63 | 1.5 | 1.56 | 3.44 | 1.56 | 6.72 | 6.75 | 6.07 | 0.5 | 9.50 | 8 | 7/8 | 3/4 | |
| 8 | 13.5 | 1.06 | 1.12 | 9.69 | 8.63 | 1.69 | 1.75 | 3.94 | 1.75 | 8.72 | 8.75 | 7.98 | 0.5 | 11.75 | 8 | 7/8 | 3/4 | |
| 10 | 16 | 1.12 | 1.19 | 12 | 10.75 | 1.88 | 1.94 | 3.94 | 1.94 | 10.88 | 10.92 | 10.02 | 0.5 | 14.25 | 12 | 1 | 7/8 | |
| 12 | 19 | 1.19 | 1.25 | 14.38 | 12.75 | 2.12 | 2.19 | 4.44 | 2.19 | 12.88 | 12.92 | 12 | 0.5 | 17.00 | 12 | 1 | 7/8 | |
| 14 | 21 | 1.31 | 1.38 | 15.75 | 14 | 2.19 | 3.12 | 4.94 | 2.25 | 14.14 | 14.18 | 0.5 | 18.75 | 12 | 1 1/8 | 1 | ||
| 16 | 23.5 | 1.38 | 1.44 | 18 | 16 | 2.44 | 3.44 | 4.94 | 2.5 | 16.16 | 16.19 | 0.5 | 21.26 | 16 | 1 1/8 | 1 | ||
| 18 | 25 | 1.5 | 1.56 | 19.88 | 18 | 2.62 | 3.81 | 5.44 | 2.69 | 18.18 | 18.2 | 0.5 | 22.75 | 16 | 1 1/4 | 1 1/8 | ||
| 20 | 27.5 | 1.62 | 1.69 | 22 | 20 | 2.81 | 4.06 | 5.62 | 2.88 | 20.2 | 20.25 | 0.5 | 25.00 | 20 | 1 1/4 | 1 1/8 | ||
| 22 | 29.5 | 1.75 | 1.81 | 24 | 22 | 3.06 | 4.25 | 5.82 | 22.22 | 22.25 | 0.5 | 27.25 | 20 | 1 3/8 | 1 1/4 | |||
| 24 | 32 | 1.81 | 1.88 | 26.12 | 24 | 3.19 | 4.38 | 5.94 | 3.25 | 24.25 | 24.25 | 0.5 | 29.50 | 20 | 1 3/8 | 1 1/4 |
| NPS | SO | THD | SW | LAP | BL | WN |
|---|---|---|---|---|---|---|
| 1/2 | 1 / 0.45 | 1 / 0.45 | 2 / 0.91 | 1 / 0.45 | 2 / 0.91 | 2 / 0.91 |
| 3/4 | 2 / 0.91 | 2 / 0.91 | 2 / 0.91 | 2 / 0.91 | 2 / 0.91 | 2 / 0.91 |
| 1 | 2 / 0.91 | 2 / 0.91 | 2 / 0.91 | 2 / 0.91 | 2 / 0.91 | 3 / 1.36 |
| 1-1/4 | 3 / 1.36 | 3 / 1.36 | 3 / 1.36 | 3 / 1.36 | 3 / 1.36 | 3 / 1.36 |
| 1-1/2 | 3 / 1.36 | 3 / 1.36 | 3 / 1.36 | 3 / 1.36 | 4 / 1.81 | 4 / 1.81 |
| 2 | 5 / 2.27 | 5 / 2.27 | 5 / 2.27 | 5 / 2.27 | 5 / 2.27 | 6 / 2.72 |
| 2-1/2 | 8 / 3.63 | 8 / 3.63 | 8 / 3.63 | 8 / 3.63 | 7 / 3.18 | 10 / 4.54 |
| 3 | 9 / 4.08 | 9 / 4.08 | 9 / 4.08 | 9 / 4.08 | 9 / 4.08 | 11.5 / 5.22 |
| 3-1/2 | 11 / 4.99 | 12 / 5.44 | 11 / 4.99 | 11 / 4.99 | 13 / 5.90 | 12 / 5.44 |
| 4 | 13 / 5.90 | 13 / 5.90 | 13 / 5.90 | 13 / 5.90 | 17 / 7.71 | 16.5 / 7.48 |
| 5 | 15 / 6.80 | 15 / 6.80 | 15 / 6.80 | 15 / 6.80 | 20 / 9.07 | 21 / 9.53 |
| 6 | 19 / 8.62 | 19 / 8.62 | 19 / 8.62 | 19 / 8.62 | 27 / 12.25 | 26 / 11.79 |
| 8 | 30 / 13.61 | 30 / 13.61 | 30 / 13.61 | 30 / 13.61 | 47 / 21.32 | 42 / 19.05 |
| 10 | 43 / 19.50 | 43 / 19.50 | 43 / 19.50 | 43 / 19.50 | 70 / 31.75 | 54 / 24.49 |
| 12 | 64 / 29.03 | 64 / 29.03 | 64 / 29.03 | 64 / 29.03 | 123 / 55.79 | 88 / 39.92 |
| 14 | 90 / 40.82 | 90 / 40.82 | 90 / 40.82 | 105 / 47.63 | 140 / 63.50 | 114 / 51.71 |
| 16 | 106 / 48.08 | 98 / 44.45 | 98 / 44.45 | 140 / 63.50 | 180 / 81.65 | 140 / 63.50 |
| 18 | 130 / 58.97 | 130 / 58.97 | 130 / 58.97 | 160 / 72.57 | 220 / 99.79 | 165 / 74.84 |
| 20 | 165 / 74.84 | 165 / 74.84 | 165 / 74.84 | 195 / 88.45 | 285 / 129.27 | 197 / 89.36 |
| 22 | 185 / 83.91 | 185 / 83.91 | 185 / 83.91 | 245 / 111.13 | 355 / 161.03 | 225 / 102.06 |
| 24 | 220 / 99.79 | 220 / 99.79 | 220 / 99.79 | 275 / 124.74 | 430 / 195.04 | 268 / 121.56 |
Note: The above data is for reference only. Please refer to the ASME B16.5 standard for design and production.
ASME B16.5 Class 150 flanges are the most widely used piping components in industrial systems, providing reliable sealing performance for low-pressure pipelines across oil & gas, chemical processing, water treatment, and power generation. With standardized dimensions covering NPS 1/2″ to 24″, Class 150 flanges ensure full compatibility, safe installation, and interchangeability among global manufacturers. Understanding their exact dimensions, hub sizes, thickness, bore, and weight is essential for engineers, procurement teams, and project designers seeking safe and cost-effective flange solutions.
ASME B16.5 Class 150 Flange Dimensions refer to the dimensional data of flanges with a pressure rating of Class 150 as specified in the ASME B16.5 standard.
They define how large and how thick a Class 150 flange should be for each NPS size, including the required number and size of bolt holes.
Regardless of whether the flange is made from carbon steel, stainless steel, Inconel, Duplex, or copper-nickel alloys, the dimensions of an ASME B16.5 Class 150 flange are always identical.
Different materials only affect the pressure–temperature rating, not the flange dimensions.
What is Class 150?
Class 150 is a pressure rating within the ASME B16.5 standard.
It represents the maximum allowable pressure at various temperatures.
It does not mean that the flange can only withstand 150 psi. The allowable pressure varies with temperature.
For example (using ASTM A105 material):
| Temperature (°C) | Max. Pressure (bar) |
| −29 to 38°C | 19.6 bar |
| 100°C | 17.7bar |
| 200°C | 13.8 bar |
Therefore, Class 150 is simply a rating designation, not a fixed pressure value.
Characteristics of Class 150 Flanges
- The lowest pressure class within ASME B16.5
- Suitable for low-pressure piping systems
- Common in water, gas, air, steam, and light chemical applications
- Fully standardized and globally accepted
- Most widely used, widely available, and cost-effective
Whether you are selecting Slip-On, Welding Neck, Socket Weld, Lap Joint, or Blind flanges, ASME B16.5 Class 150 provides a complete dimensional framework that guarantees consistency and reliability across every piping application. By referencing the standardized dimensions and weight ranges, engineers and buyers can confidently specify the correct flange for their pressure class and operating conditions. For detailed catalogs, material options, or custom forging requirements, contact us to receive professional technical support and ASME-certified flange solutions.
