ASME B16.9 Table 4 provides dimensions of short radius returns from size 1” to 24”. These fittings are also sparingly used in actual piping network. They are mostly used to construct heating coils of heat exchangers and atmospheric vents on storage tanks etc. They have a higher pressure drop and used when there is a space constraint. This page provides metric dimensions for short radius returns.
Available Dimensions are : OD | Outside Diameter at Bevel, O | Center to Center Distance, K | Back to Face Distance.
| NPS | OD | O | K |
|---|---|---|---|
| 1 | 33.4 | 51 | 41 |
| 1-1?4 | 42.2 | 64 | 52 |
| 1-1?2 | 48.3 | 76 | 62 |
| 2 | 60.3 | 102 | 81 |
| 2-1?2 | 73.0 | 127 | 100 |
| 3 | 88.9 | 152 | 121 |
| 3-1?2 | 101.6 | 178 | 140 |
| 4 | 114.3 | 203 | 159 |
| 5 | 141.3 | 254 | 197 |
| 6 | 168.3 | 305 | 237 |
| 8 | 219.1 | 406 | 313 |
| 10 | 273.0 | 508 | 391 |
| 12 | 323.8 | 610 | 467 |
| 14 | 355.6 | 711 | 533 |
| 16 | 406.4 | 813 | 610 |
| 18 | 457.0 | 914 | 686 |
| 20 | 508.0 | 1016 | 762 |
| 22 | 559.0 | 1118 | 838 |
| 24 | 610.0 | 1219 | 914 |
GENERAL NOTES:
(a) All dimensions are in millimeters.
(b) Dimension A is equal to one-half of dimension O.
