Pipe Flanges and Gasket Dimensions
Gasket dimensions according ASME B16.5 Pipe Flanges and Flange Fittings.
Gasket dimensions for ASME B16.5 Pipe Flanges and Flange Fittings:
| Nominal Pipe Size | Gasket Inside Diameter - ID - (inch) |
Gasket Outside Diameter - OD - (inches) | ||||
|---|---|---|---|---|---|---|
| Class 150 | Class 300 | Class 400 | Class 600 | Class 900 | ||
| 1/2 | 0.84 | 1.875 | 2.125 | 2.125 | 2.125 | 2.50 |
| 3/4 | 1.06 | 2.25 | 2.625 | 2.625 | 2.625 | 2.75 |
| 1 | 1.31 | 2.625 | 2.875 | 2.875 | 2.875 | 3.125 |
| 1 1/4 | 1.66 | 3 | 3.25 | 3.25 | 3.25 | 3.50 |
| 1 1/2 | 1.91 | 3.375 | 3.75 | 3.75 | 3.75 | 3.875 |
| 2 | 2.38 | 4.125 | 4.375 | 4.375 | 4.375 | 5.625 |
| 2 1/2 | 2.88 | 4.875 | 5.125 | 5.125 | 5.125 | 6.50 |
| 3 | 3.50 | 5.375 | 5.875 | 5.875 | 5.875 | 6.625 |
| 4 | 4.50 | 6.875 | 7.125 | 7.00 | 7.625 | 8.125 |
| 5 | 5.56 | 7.75 | 8.50 | 8.375 | 9.50 | 9.75 |
| 6 | 6.62 | 8.75 | 9.875 | 9.75 | 10.50 | 11.375 |
| 8 | 8.62 | 11 | 12.125 | 12.00 | 12.625 | 14.125 |
| 10 | 10.75 | 13.375 | 14.25 | 14.125 | 15.75 | 17.125 |
| 12 | 12.75 | 16.125 | 16.625 | 16.50 | 18.00 | 19.625 |
The ASME B16.5 - 1996 Pipe Flanges and Flange Fittings standard covers pressure-temperature ratings, materials, dimensions, tolerances, marking, testing, and methods of designating openings for pipe flanges and flanged fittings.
The standard includes flanges with rating class designations 150, 300, 400, 600, 900, 1500, and 2500 in sizes NPS 1/2 through NPS 24, with requirements given in both metric and U.S units. The Standard is limited to flanges and flanged fittings made from cast or forged materials, and blind flanges and certain reducing flanges made from cast, forged, or plate materials. Also included in this Standard are requirements and recommendations regarding flange bolting, flange gaskets, and flange joints.