Technical information / Connection standards / ASME B16.5 · Blind flange
End connection standard
ASME B16.5 · BLIND
Blind flange dimensions
The CSV uses semicolons as separators. The link carries the selected class and size.
| NPS | DN | D | k | n | lhole | b | g | f | kg |
|---|---|---|---|---|---|---|---|---|---|
| 1/2" | DN15 | 89 | 60.3 | 4 | 15.9 | 11.1 | 34.9 | 1.6 | 0.42 |
| 3/4" | DN20 | 98 | 69.8 | 4 | 15.9 | 12.7 | 42.9 | 1.6 | 0.61 |
| 1" | DN25 | 108 | 79.4 | 4 | 15.9 | 14.3 | 50.8 | 1.6 | 0.86 |
| 1 1/4" | DN32 | 117 | 88.9 | 4 | 15.9 | 15.9 | 63.5 | 1.6 | 1.16 |
| 1 1/2" | DN40 | 127 | 98.4 | 4 | 15.9 | 17.5 | 73.2 | 1.6 | 1.53 |
| 2" | DN50 | 152 | 120.6 | 4 | 19 | 19 | 92.1 | 1.6 | 2.41 |
| 2 1/2" | DN65 | 178 | 139.7 | 4 | 19.1 | 22.3 | 104.6 | 1.6 | 3.97 |
| 3" | DN80 | 190 | 152.4 | 4 | 19 | 23.8 | 127 | 1.6 | 4.9 |
| 3 1/2" | DN90 | 216 | 177.8 | 8 | 19.1 | 23.9 | 139.7 | 1.6 | 6.21 |
| 4" | DN100 | 229 | 190.5 | 8 | 19 | 23.8 | 157.2 | 1.6 | 7.03 |
| 5" | DN125 | 254 | 215.9 | 8 | 22.2 | 23.8 | 185.7 | 1.6 | 8.63 |
| 6" | DN150 | 279 | 241.3 | 8 | 22.2 | 25.4 | 215.9 | 1.6 | 11.3 |
| 8" | DN200 | 343 | 298.4 | 8 | 22.2 | 28.6 | 269.9 | 1.6 | 19.6 |
| 10" | DN250 | 406 | 362 | 12 | 25.4 | 30.2 | 323.8 | 1.6 | 28.7 |
| 12" | DN300 | 483 | 431.8 | 12 | 25.4 | 31.8 | 381 | 1.6 | 43.4 |
| 14" | DN350 | 533 | 476.2 | 12 | 28.6 | 34.9 | 412.7 | 1.6 | 58 |
| 16" | DN400 | 597 | 539.7 | 16 | 28.6 | 36.5 | 469.9 | 1.6 | 76.1 |
| 18" | DN450 | 635 | 577.8 | 16 | 31.8 | 39.7 | 533.4 | 1.6 | 93.7 |
| 20" | DN500 | 698 | 635 | 20 | 31.8 | 42.9 | 584.2 | 1.6 | 122.3 |
| 22" | DN550 | 750 | 692.1 | 20 | 34.9 | 46 | 641.2 | 1.6 | 151.4 |
| 24" | DN600 | 813 | 749.3 | 20 | 34.9 | 47.6 | 692.1 | 1.6 | 185.3 |
Notes
- This table has been compiled by Emsal from the relevant standards. For the full text of the standard, refer to ASME.
- Connection dimensions and thickness are the same as the slip-on flange of the same class and size; dimensions are converted from the standard's inch values.
- Raised face (f): 1.6 mm for Class 150 and 300 and included in the thickness (b); 6.4 mm for Class 600 and 900 and not included in the thickness (ASME B16.5).
- Weights are calculated including the raised face (7.85 kg/dm³).
- Accuracy and currency are not guaranteed; use the current edition of the standard for design and purchasing decisions. How the library is compiled →
Dimension letters
| D | Flange outside diameter | g | Raised face diameter |
| k | Bolt circle diameter | f | Raised face height |
| l | Bolt hole diameter | n | Number of bolts |
| b | Flange thickness |
Joint type and P&ID symbol
A blind flange closes the end of a line or nozzle; it has no pipe. It can be bolted to any flange type of the same class (weld neck in the diagram).
flangepipegasketweldbolt, nut
- Choose a blind flange with the same PN / Class and DN as the mating flange.
- Fit the gasket and tighten the bolts in a cross pattern.
- Also used to close line ends during pressure tests.
Used where a line will be extended later, at cleaning and inspection openings and at line ends during testing. Because the plate carries the full pressure, it is thicker than other flanges of the same class.
P&ID: Blind flangeA heavier line opposite the flange line at the end of the pipe: the line is blanked. Symbol library →
Not to scale; proportions are indicative.
