Service Life for Technical Parts Under Mainly Static Loads

2 Service Life for Technical Parts Under Mainly Static Loads 1.6.3.2.1 Acquiring Permissible Load 

As a rule, all technical components are dimensioned such that their expected service life is longer than the lifetime for which they are to be warranted. This is also true for each individual part, unless originally configured to be a wear part and characterized as such. All aspects of a particular load must be taken into consideration type, duration, temperature, media exposure, processing and post-processing operations. 

Despite the progress made in computer-aided treatment of structure-property relationships, dimensioning under such complex conditions continues to depend on experimental results obtained in creep investigations, S-N diagrams, as well as media and weathering investigations. 

ISO 9080 [114] describes a standard extrapolation method, abbreviated SEM, for predicting the service life creep behavior of pipes. The SEM method involves internal pressure tests at two or more temperatures, linear regression analysis with an estimation of regression quality, curve fitting and three different ways of expressing bend in hydrostatic pressure measurement. 

Left service iife determination under certain materia is and operating conditions (t = time, T = temperature, M = medium, P = processing)) 

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