Flange Dimension Tables
Access comprehensive tables for various flange standards, including dimensions, bolt patterns, and gasket requirements. Essential data for engineers and designers.
ASME B16.5 Class 150 Dimensions (inches & mm)
Detailed dimensions for Class 150 flanges, covering nominal pipe sizes, outside diameter, bolt circle diameter, and bolt hole sizes.
| NPS | OD (in) | OD (mm) | Bolt Circle (in) | Bolt Circle (mm) | No. Bolts | Bolt Size (in) |
|---|---|---|---|---|---|---|
| 1/2 | 3.50 | 88.9 | 2.38 | 60.5 | 4 | 1/2 |
| 3/4 | 3.88 | 98.6 | 2.75 | 69.9 | 4 | 1/2 |
| 1 | 4.25 | 108.0 | 3.12 | 79.2 | 4 | 1/2 |
| 1 1/4 | 4.62 | 117.3 | 3.50 | 88.9 | 4 | 1/2 |
| 1 1/2 | 5.00 | 127.0 | 3.88 | 98.6 | 4 | 1/2 |
| 2 | 6.00 | 152.4 | 4.75 | 120.7 | 4 | 5/8 |
| 2 1/2 | 7.00 | 177.8 | 5.50 | 139.7 | 4 | 5/8 |
| 3 | 7.50 | 190.5 | 6.00 | 152.4 | 4 | 5/8 |
| 4 | 9.00 | 228.6 | 7.50 | 190.5 | 8 | 5/8 |
| 6 | 11.00 | 279.4 | 9.50 | 241.3 | 8 | 3/4 |
| 8 | 13.50 | 342.9 | 11.75 | 298.5 | 8 | 3/4 |
| 10 | 16.00 | 406.4 | 14.25 | 362.0 | 12 | 7/8 |
| 12 | 19.00 | 482.6 | 17.00 | 431.8 | 12 | 7/8 |
ASME B16.5 Class 300 Dimensions
Specifications for Class 300 flanges, including face-to-face dimensions and bolt configurations for higher pressure applications.
| NPS | OD (in) | OD (mm) | Bolt Circle (in) | Bolt Circle (mm) | No. Bolts | Bolt Size (in) |
|---|---|---|---|---|---|---|
| 1/2 | 3.75 | 95.3 | 2.62 | 66.7 | 4 | 1/2 |
| 3/4 | 4.62 | 117.3 | 3.25 | 82.6 | 4 | 5/8 |
| 1 | 4.88 | 123.9 | 3.50 | 88.9 | 4 | 5/8 |
| 1 1/4 | 5.25 | 133.4 | 3.88 | 98.6 | 4 | 5/8 |
| 1 1/2 | 6.12 | 155.4 | 4.50 | 114.3 | 4 | 3/4 |
| 2 | 6.50 | 165.1 | 5.00 | 127.0 | 8 | 5/8 |
| 2 1/2 | 7.50 | 190.5 | 5.88 | 149.2 | 8 | 3/4 |
| 3 | 8.25 | 209.6 | 6.62 | 168.3 | 8 | 3/4 |
| 4 | 10.75 | 273.1 | 8.50 | 215.9 | 8 | 3/4 |
| 6 | 12.50 | 317.5 | 10.62 | 269.9 | 12 | 3/4 |
| 8 | 15.00 | 381.0 | 13.00 | 330.2 | 12 | 7/8 |
| 10 | 17.50 | 444.5 | 15.25 | 387.4 | 16 | 7/8 |
| 12 | 20.50 | 520.7 | 17.75 | 450.9 | 16 | 1 |
ASME B16.47 Series A & B Dimensions
Large diameter flange dimensions for Series A (MSS SP-44) and Series B (API 605) flanges, commonly used in process piping.
| NPS | Class | Series | OD (in) | Bolt Circle (in) | No. Bolts | Bolt Size (in) |
|---|---|---|---|---|---|---|
| 26 | 150 | A | 34.00 | 31.75 | 20 | 1 1/4 |
| 26 | 150 | B | 32.00 | 29.50 | 20 | 1 1/8 |
| 30 | 150 | A | 38.00 | 35.50 | 24 | 1 1/4 |
| 30 | 150 | B | 36.00 | 33.00 | 24 | 1 1/8 |
| 36 | 150 | A | 45.00 | 42.00 | 28 | 1 1/2 |
| 36 | 150 | B | 43.00 | 39.50 | 28 | 1 1/4 |
ANSI vs ASME Flange Comparison Table
A comparison of key differences and equivalencies between ANSI and ASME flange standards.
| Feature | ANSI B16.5 (Historical) | ASME B16.5 (Current) |
|---|---|---|
| Scope | Covers pipe flanges and flanged fittings | Covers pipe flanges and flanged fittings |
| Pressure-Temp Ratings | Defined | Defined |
| Dimensions | Similar, but ASME is the current standard | Current standard for dimensions |
| Material | Specified | Specified |
| Interchangeability | Generally interchangeable with ASME B16.5 | Generally interchangeable with ANSI B16.5 |
PN Flange Conversion (PN6, PN10, PN16, PN40)
Conversion chart for Pressure Nominal (PN) rated flanges to their approximate ASME Class equivalents and common pressure ratings.
| PN Rating | Approx. ASME Class | Max Pressure (bar) | Max Pressure (psi) |
|---|---|---|---|
| PN6 | Class 150 (lower end) | 6 | 87 |
| PN10 | Class 150 | 10 | 145 |
| PN16 | Class 150 | 16 | 232 |
| PN25 | Class 150 / 300 | 25 | 362 |
| PN40 | Class 300 | 40 | 580 |
Flange Bolt & Gasket Dimension Tables
Essential data for selecting correct bolts and gaskets for various flange sizes and pressure classes.
| NPS | Class | No. Bolts | Bolt Size (in) | Gasket OD (in) | Gasket ID (in) |
|---|---|---|---|---|---|
| 2 | 150 | 4 | 5/8 | 2.88 | 2.06 |
| 2 | 300 | 8 | 5/8 | 2.88 | 2.06 |
| 4 | 150 | 8 | 5/8 | 4.88 | 4.06 |
| 4 | 300 | 8 | 3/4 | 4.88 | 4.06 |