Pipe support - design for stress or allowed deflection under load ?

In piping stress analysis, boundary conditions are ensured by piping supports. If non-resilient (stiff) supports deflect appreciably while remaining OK from allowable stress for support perspective, piping stress analysis results become unreliable - some supports can lift off, expansion stress get over estimated with 10^12 lb/in or lb in/deg consideration, equipment nozzle load may get under conservative, too!

In non-nuclear static piping analysis, how many of us consider default support stiffness other than the 10^12 lb/in or lb in/deg consideration of CII ? In nuclear piping analysis with dynamic seismic and shock loads, we require specification of minimum support stiffness required to structual depts.

Can,t Caesar-II provide some suitable standard support stiffness - if avaiable from past projects data ?


reg,
sam