Tee vs Weldolet vs Stub-in Branch Fitting Selector | Synbase Steel
Branch Connection Selector: Tee vs Olet vs Stub-in
There is no single code rule — the choice is total installed cost and stress, not sticker price. This routes on branch ratio and service.
Branch : run size
Size-on-size (branch = run)
One size down (e.g. 6″×4″)
Off-ratio small (e.g. ≤1/3 of run)
Run size
2″ NPS or below
Above 2″ NPS
Service severity
Standard pressure
High-pressure / cyclic fatigue (B31.3 Ch IX)
High-temperature creep
Header condition
Single branch
Multi-branch / vibration
Logic from ASME B31.3 (both reducing tees and integrally-reinforced branch fittings permitted) + piping-engineering practice. Final selection is subject to your stress analysis.