Limitations of tees with branches of equal diameter

Welded and necked-out tees are frequently used in pressure vessel and pipin g design. Standard calculations based on the Kellog method are merely appli cable for pressure loading. Supplementary forces and moments are excluded i n this case. The application of numerical methods of structural analysis is extremely helpful in this situation. However, detailed modelling of the ge ometry is quite complicated and standard models of the cylinder-cylinder in ter section type cannot be used. Special models of the welded and necked-ou t design variants have to be generated and parametrized in order to be appl icable for different nominal sizes. Tees as structural components have to b e considered under various aspects with respect to their mechanical behavio ur. The following investigation proposes methods for design under static an d cyclic loading conditions based on detailed FE analyses. The results reve al a considerable potential of tees which has to be proved by analysis.