ASME B16.21 Non-Metallic Flat Gasket Dimensions
Dimensions of ASME B16.21 non-metallic flat ring gaskets for ASME B16.5 raised-face flanges in millimetres: inside diameter and outside diameter for Class 150, 300 and 600.
Ring gaskets sit inside the bolt circle and are cut from compressed non-asbestos fibre, graphite, PTFE or rubber sheet.
ASME B16.21 Non-Metallic Flat Gasket dimensions — tables
Flat ring gaskets for raised-face flanges (mm)
| NPSin | IDInside dia | ODClass 150 | ODClass 300 | ODClass 600 |
|---|---|---|---|---|
| ½" | 21 | 48 | 54 | 54 |
| ¾" | 27 | 57 | 67 | 67 |
| 1" | 33 | 67 | 73 | 73 |
| 1¼" | 42 | 76 | 83 | 83 |
| 1½" | 48 | 86 | 95 | 95 |
| 2" | 60 | 105 | 111 | 111 |
| 2½" | 73 | 124 | 130 | 130 |
| 3" | 89 | 137 | 149 | 149 |
| 3½" | 102 | 162 | 165 | 162 |
| 4" | 114 | 175 | 181 | 194 |
| 5" | 141 | 197 | 216 | 241 |
| 6" | 168 | 222 | 251 | 267 |
| 8" | 219 | 279 | 308 | 321 |
| 10" | 273 | 340 | 362 | 400 |
| 12" | 324 | 410 | 422 | 457 |
| 14" | 356 | 451 | 486 | 492 |
| 16" | 406 | 514 | 540 | 565 |
| 18" | 457 | 549 | 597 | 613 |
| 20" | 508 | 606 | 654 | 683 |
| 24" | 610 | 718 | 775 | 791 |
Notes
- Dimensions are in millimetres unless stated otherwise.
- Values are rounded to the nearest millimetre; some published tables differ by 1 mm.
Reference information compiled from the published standard for convenience. It does not replace the current edition of the governing standard, which takes precedence. Verify critical dimensions and properties before design, purchase or fabrication. Teshi Engineers & Sales Promoters (P) Ltd accepts no liability for errors or omissions.
Related products, data sheets and standards
Spiral Wound Gasket
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OpenEquivalent and related standards to ASME B16.21 Non-Metallic Flat Gasket Dimensions
All equivalents| Region | Standard | Relationship |
|---|---|---|
| Europe | EN 1514-1 / -2 / -4 / EN 12560 | Gaskets for PN and Class flanges |
| China | GB/T 4622.2 / HG/T 20610 / HG/T 20631 | Spiral-wound gaskets for PN and Class flanges |
| China | HG/T 20612 / HG/T 20633 | Ring joint and metal gaskets |
| Japan | JIS B2404 | Gasket dimensions for JIS flanges |
Teshi Group manufactures flanges and fittings to all of these standards on request, including Chinese GB / HG / SH and European EN dimensions for export projects. Always confirm bolting, facing and thickness when substituting one standard for another.
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