Butt Weld Fitting Dimensions (ASME B16.9)
This elbow dimensions chart and fittings table gives the main dimensions of ASME B16.9 butt-weld fittings from ½" to 24" NPS: centre-to-end dimensions of 90° and 45° long radius elbows and 90° short radius elbows, centre-to-end of equal tees, length of concentric and eccentric reducers, and length of caps. These dimensions are the same for every material and wall thickness of the fitting, so piping layouts can be drawn before the material is chosen.
Elbow dimensions
| NPS | OD | 90° LR | 45° LR | 90° SR |
|---|---|---|---|---|
| ½ | 21.3 | 38 | 16 | – |
| ¾ | 26.7 | 38 | 19 | – |
| 1 | 33.4 | 38 | 22 | 25 |
| 1¼ | 42.2 | 48 | 25 | 32 |
| 1½ | 48.3 | 57 | 29 | 38 |
| 2 | 60.3 | 76 | 35 | 51 |
| 2½ | 73.0 | 95 | 44 | 64 |
| 3 | 88.9 | 114 | 51 | 76 |
| 4 | 114.3 | 152 | 64 | 102 |
| 5 | 141.3 | 190 | 79 | 127 |
| 6 | 168.3 | 229 | 95 | 152 |
| 8 | 219.1 | 305 | 127 | 203 |
| 10 | 273.1 | 381 | 159 | 254 |
| 12 | 323.9 | 457 | 190 | 305 |
| 14 | 355.6 | 533 | 222 | 356 |
| 16 | 406.4 | 610 | 254 | 406 |
| 18 | 457.0 | 686 | 286 | 457 |
| 20 | 508.0 | 762 | 318 | 508 |
| 24 | 610.0 | 914 | 381 | 610 |
Long radius elbows have a centreline radius of 1.5 × NPS (for ¾" and above); short radius elbows 1.0 × NPS. The outside diameter at the bevel equals the pipe outside diameter.
Tee, reducer and cap dimensions
| NPS | Equal tee C / M | Reducer length H | Cap length E |
|---|---|---|---|
| ½ | 25 | – | 25 |
| ¾ | 29 | 38 | 25 |
| 1 | 38 | 51 | 38 |
| 1¼ | 48 | 51 | 38 |
| 1½ | 57 | 64 | 38 |
| 2 | 64 | 76 | 38 |
| 2½ | 76 | 89 | 38 |
| 3 | 86 | 89 | 51 |
| 4 | 105 | 102 | 64 |
| 5 | 124 | 127 | 76 |
| 6 | 143 | 140 | 89 |
| 8 | 178 | 152 | 102 |
| 10 | 216 | 178 | 127 |
| 12 | 254 | 203 | 152 |
| 14 | 279 | 330 | 165 |
| 16 | 305 | 356 | 178 |
| 18 | 343 | 381 | 203 |
| 20 | 381 | 508 | 229 |
| 24 | 432 | 508 | 267 |
For reducing tees, the run dimension C is the same as the equal tee and the outlet dimension M is listed in B16.9 for each branch size. Reducer length is the same for all small-end sizes of a given large end. Cap length E applies to standard wall thicknesses; heavier caps have a longer length E1, listed in B16.9.
Notes
Dimensions are from ASME B16.9 and are given for guidance; always refer to the current edition and the project specification. Wall thickness at the ends matches the pipe schedule ordered – see the pipe schedule chart. Our fittings in every material are on the pipe fittings page, including elbows, stainless steel pipe fittings, carbon steel pipe fittings and ASTM A234 WPB fittings. More charts are on the technical resources page.
Frequently Asked Questions
Under ASME B16.9, a 6" 90° long radius elbow has a centre-to-end dimension of 229 mm.
LR elbows have a centre-to-end of 1.5 × NPS and SR elbows 1.0 × NPS; for a 4" elbow, 152 mm and 102 mm.
No. B16.9 centre-to-end and length dimensions are the same for all wall thicknesses, except cap length, which is longer for heavy walls.
Under ASME B16.9, a reducer with a 6" large end is 140 mm long.