Design equations for plastic tanks are being developed in a long term research work at the university of Dortmund. As part of this work a mechanical stress analysis has been made for the non-radial, tangential inclined nozzle. Parameter studies with different designed nozzle/cylindrical shell intersections have been carried out by variation of the important geometrical dimensions. Due to non-linear mechanical stress analysis of notched bars correcting factors were determined that take into consideration the different stress-strain behaviour of the plastic materials. As the results of the examination design rules are offered which take into account the special material behaviour of the plastics.