[en] When response spectrum methods are used in the seismic analysis of piping systems the response due to inertial action, the dynamic response, and the response due to the time varying differential motions of the support points (the pseudo-static response) must be determined. In this study the adequacy and the degree of conservatism associated with the uniform response spectrum method, the center of mass response spectrum method and fourteen variants of the independent response spectrum method to compute the dynamic response and five different methods to compute the pseudo-static response were evaluated. For this purpose a sample of six piping systems, two of which were subjected to thirty-three earthquakes, were studied. For each system and seismic excitation a multiple independent support excitation time history analysis was developed and used to provide a best estimate of true response and to form the basis for comparison. A combination procedure to calculate the total responses is considered as well. Results are presented and compared to the corresponding responses evaluated using the current uniform response spectrum method and the center of mass response spectra approach. Based on the results, recommendations concerning the use of the methods were developed