Hi all,

Firstly I would define true installation temperature to be the temperature of the piping when the final closure weld / joint is made for a section of piping between anchors or control points. As the piping fabrication and erection occurs at different points of time when the ambient temperatures are different we cannot precisely tell the true installation temperature for the piping of interest. Keeping this situation in mind we have to decide a single installation temperature for stress analysis calculations by considering the range of ambient temperatures from minimum ambient to maximum ambient temperature to which the piping is subjected during installation, that would ensure the maximum possible stresses and reaction forces are checked.

ASME B31.3 319.3.1(b) makes it mandatory to compute the values for reactions as algebraic difference between the value at maximum(or min) temperature for the thermal ccle under analysis and the value at the temperature expected during installation. However I have the correct maximum ambient and minimum ambient for the site location, and cannot decide the true installation temperature, as I do not know when the piping is going to be fabricated and erected.

Can anyone tell me how best the "installation temperature" as given in 319.3.1(b) of ASME B31.3 be approximated.