| Do | Outside diameter of tee header |
| mm |
| T | Wall thickness of tee header |
| mm |
| Tb | Wall thickness of tee branch |
| mm |
| do | Outside diameter of tee branch |
| mm |
| rc | Tee crotch radius 0.05 dbo ≤ rc ≤ (0.1 dbo + 12.5) |
| mm |
| Lh | Half width reinforcement length on the header minimum: Lh ≥ di |
| mm |
| Lb | Reinforcement length on branch from the outer surface of the header minimum: Lb ≥ 0.7 √(do Tb) |
| mm |
| Not entered in CAESAR II |
| di | Inside diameter of tee branch di = do − 2Tb |
| mm |
| dbo | Outside diameter of attached branch pipe |
| mm |
