In large industrial installations the issue of how to estimate the actual earthquake response of equipment supported in structures becomes a serious consideration when evaluating the expected availability of the installation after the occurrence of a major earthquake event. In the work reported here a comparison of the design results using ASCE-7 and NCh2369 are compared with Response Spectrum and Time-History analysis with the actual earthquake spectrum and ground motion records of the large earthquake that took place in Chile in 2010-02-27 (Mw = 8.8). These analyses are carried out for two different structures, a Gas-Gas Heater with the associated ducting in a Flue Gas Desulphurization System Support Structure and a Steam Turbine - Generator System with its foundation structure. The comparison of the results obtained with the different analyses procedures allows identifying several aspects in which the standard design procedure does not provide assurance of appropriate behavior in equipment under earthquake action. The quality of the correlation between the design results and the different analyses is seen to be quite different. While some elements are over designed, for other elements the analysis completely misrepresents the Time-History results. These results allow providing recommendations on the scope of applicability of the different approaches found in the codes based on how well the different procedures are able to predict the computed performance of the equipment under earthquake action.