ASME B16.9 Fitting Dimensions
Standard butt-weld fitting dimensions for 90° elbows, 45° elbows, equal tees, and concentric/eccentric reducers. NPS 1/2" to 24".
Complete Dimension Chart
All dimensions in millimeters. ASME B16.9 standard.
| NPS | 90° Elbow A | 45° Elbow B | Tee C | Tee M | Reducer H |
|---|---|---|---|---|---|
| 0.5" | 38 | 16 | 25 | 25 | — |
| 0.75" | 38 | 19 | 29 | 29 | — |
| 1" | 38 | 22 | 38 | 38 | 51 |
| 1.25" | 48 | 25 | 48 | 48 | 51 |
| 1.5" | 48 | 29 | 57 | 57 | 64 |
| 2" | 60 | 35 | 64 | 64 | 76 |
| 2.5" | 76 | 44 | 76 | 76 | 89 |
| 3" | 86 | 51 | 86 | 86 | 102 |
| 3.5" | 95 | 57 | 95 | 95 | 108 |
| 4" | 105 | 64 | 105 | 105 | 127 |
| 5" | 124 | 79 | 124 | 124 | 152 |
| 6" | 143 | 95 | 143 | 143 | 178 |
| 8" | 178 | 127 | 178 | 178 | 229 |
| 10" | 216 | 159 | 216 | 216 | 279 |
| 12" | 254 | 190 | 254 | 254 | 330 |
| 14" | 279 | 222 | 279 | 279 | 381 |
| 16" | 305 | 254 | 305 | 305 | 432 |
| 18" | 343 | 279 | 343 | 343 | 483 |
| 20" | 381 | 305 | 381 | 381 | 533 |
| 22" | 419 | 343 | 419 | 419 | 584 |
| 24" | 432 | 381 | 432 | 432 | 660 |
Fitting Types & Applications
90° Long Radius Elbow
Most common elbow for direction change. Center-to-end dimension = 1.5 × NPS.
A = 1.5 × NPS
45° Elbow
Gradual direction change, less pressure drop than 90°.
B = 0.625 × NPS
Equal Tee
Branch connection with same bore as run pipe.
C = M = NPS
Concentric Reducer
Center-aligned bore reduction, no pocket for air/gas traps.
H = 4 × (NPS difference)
Eccentric Reducer
Flat-side reduction, used at pump suction to prevent cavitation.
H = 4 × (NPS difference)
Long Radius vs Short Radius Elbows
Long Radius (LR)
- Center radius = 1.5 × NPS
- Lower pressure drop
- Standard in process piping
- ASME B16.9 default
Short Radius (SR)
- Center radius = 1.0 × NPS
- Compact installation
- Higher pressure drop
- Only available in 90°