According to Appendix –P para 302.3.5 “The operating stress is the calculated stress at any operating condition,including pressure,weight and other sustained loads, and displacement…….The operating stress range is the range of stress between two operating conditions,including the ranges between operating conditions and a sustained case with piping at ambient temperature”

In this context I have one query.

If there are two operating cases W+P1+T1+D1 and W+P2+T2+D2 then the operating strains as calculated in this two states will be with respect to installed condition. So the corresponding stress calculations will be that of OPERATING STRESS RANGE . Can some one tell me how the OPERATING STRESS will be calculated at these individual states(including the displacement strains).