Gaskets
ASME B16.21 – Non-metallic flat gaskets for ASME B16.5 flanges
ASME B16.21 · ring and full face · NPS ½ – 24. Dimensions from the HBS technical datasheet – in stock, with EN 10204 3.1 / 3.2 certificates.
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Dimensions
ASME B16.21 dimension tables.
Ring gaskets (raised face), in inches
| NPS | ID | OD per class | ||||
|---|---|---|---|---|---|---|
| 150 | 300 | 400 | 600 | 900 | ||
| 1/2" | 0.84 | 1.88 | 2.12 | 2.12 | 2.12 | 2.50 |
| 3/4" | 1.06 | 2.25 | 2.62 | 2.62 | 2.62 | 2.75 |
| 1" | 1.31 | 2.62 | 2.88 | 2.88 | 2.88 | 3.12 |
| 1-1/4" | 1.66 | 3.00 | 3.25 | 3.25 | 3.25 | 3.50 |
| 1-1/2" | 1.91 | 3.38 | 3.75 | 3.75 | 3.75 | 3.88 |
| 2" | 2.38 | 4.12 | 4.38 | 4.38 | 4.38 | 5.62 |
| 2-1/2" | 2.88 | 4.88 | 5.12 | 5.12 | 5.12 | 6.50 |
| 3" | 3.50 | 5.38 | 5.88 | 5.88 | 5.88 | 6.62 |
| 3-1/2" | 4.00 | 6.38 | 6.50 | 6.38 | 6.38 | – |
| 4" | 4.50 | 6.88 | 7.12 | 7.00 | 7.62 | 8.12 |
| 5" | 5.56 | 7.75 | 8.50 | 8.38 | 9.50 | 9.75 |
| 6" | 6.62 | 8.75 | 9.88 | 9.75 | 10.50 | 11.38 |
| 8" | 8.62 | 11.00 | 12.12 | 12.00 | 12.62 | 14.12 |
| 10" | 10.75 | – | 14.25 | 14.12 | 15.75 | 17.12 |
| 12" | 12.75 | 16.13 | 16.62 | 16.50 | 18.00 | 19.62 |
| 14" | 14.00 | 17.75 | 19.12 | 19.00 | 19.38 | 20.50 |
| 16" | 16.00 | 20.25 | 21.25 | 21.12 | 22.25 | 22.62 |
| 18" | 18.00 | 21.62 | 23.50 | 23.38 | 24.12 | 25.12 |
| 20" | 20.00 | 23.88 | 25.75 | 25.50 | 26.88 | 27.50 |
| 24" | 24.00 | 28.25 | 30.50 | 30.25 | 31.12 | 33.00 |
Full face gaskets, class 150, in inches
| NPS | ID | OD | Number of bolt holes | Bolt hole diameter | Bolt circle diameter |
|---|---|---|---|---|---|
| 1/2" | 0.84 | 3.50 | 4 | 0.62 | 2.38 |
| 3/4" | 1.06 | 3.88 | 4 | 0.62 | 2.75 |
| 1" | 1.31 | 4.25 | 4 | 0.62 | 3.12 |
| 1-1/4" | 1.66 | 4.63 | 4 | 0.62 | 3.50 |
| 1-1/2" | 1.91 | 5.00 | 4 | 0.62 | 3.88 |
| 2" | 2.38 | 6.00 | 4 | 0.75 | 4.75 |
| 2-1/2" | 2.88 | 7.00 | 4 | 0.75 | 5.50 |
| 3" | 3.50 | 7.50 | 4 | 0.75 | 6.00 |
| 3-1/2" | 4.00 | 8.50 | 8 | 0.75 | 7.00 |
| 4" | 4.50 | 9.00 | 8 | 0.75 | 7.50 |
| 5" | 5.56 | 10.00 | 8 | 0.88 | 8.50 |
| 6" | 6.62 | 11.00 | 8 | 0.88 | 9.50 |
| 8" | 8.62 | 13.50 | 8 | 0.88 | 11.75 |
| 10" | 10.75 | 16.00 | 12 | 1.00 | 14.25 |
| 12" | 12.75 | 19.00 | 12 | 1.00 | 17.00 |
| 14" | 14.00 | 21.00 | 12 | 1.12 | 18.75 |
| 16" | 16.00 | 23.50 | 16 | 1.12 | 21.25 |
| 18" | 18.00 | 25.00 | 16 | 1.25 | 22.75 |
| 20" | 20.00 | 27.50 | 20 | 1.25 | 25.00 |
| 24" | 24.00 | 32.00 | 20 | 1.38 | 29.50 |
- ID
- Inside diameter
Dimensions in inches; mm = inch × 25.4. – : no flange of this size and class in ASME B16.5.
Dimensions in inches; mm = inch × 25.4.
Questions
ASME B16.21 – frequently asked questions.
- What is ASME B16.21?
- ASME B16.21 is the standard for non-metallic flat gaskets for asme b16.5 flanges (ASME B16.21 · ring and full face · NPS ½ – 24). HBS Solutions supplies ASME B16.21 gaskets from stock, with EN 10204 3.1 / 3.2 certificates.
- Which sizes does ASME B16.21 cover?
- The HBS datasheet lists ASME B16.21 from 1/2" to 24". The full dimension tables are on this page and in the free PDF datasheet.
- How do I order ASME B16.21 gaskets?
- Configure the part online or send your parts list through the quote form; HBS Solutions replies with a quotation within 24 hours. Stock items ship from 500.000+ pieces in stock in Almere, the Netherlands.
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