Influence of the spring hanger design on the piping flexibility and stress analysis is considered in the presented paper. Three aspects of this procedure are discussed and illustrated by the numerical examples:

- load variation criteria: different interpretations of load variability could lead to different sizes and even types of selected springs. The key issue of this problem is definition of the cold load (theoretical installed load vs. actual cold load);

- influence of the different nonlinearities (hanger's side forces due to short rod length and support's friction) on the values of calculated piping thermal movements and hence on the type of selected springs;

- modeling and interpretation of spring hanger loads within calculation of sustained stresses.

Being differently realized in the commercially available programs for piping flexibility analysis these effects are significant for flexible hot pipes and could introduce a big scattering of results.