Hi.
The WNC is only a item, with this and others items you can construct a load case, for example WNC+T1, this case simulates the pipe without fluid content and temperature T1.

In mine and metals generally we do not have high operational temperatures for the pipes, but, the pipe diameters are bigger than others piping process, for this situation we evaluate the WNC+ T1 (the case that generate the higher expansion), where T1 is the max. temp. for the pipe considerating max. solar radiation and max. environmental temp., this load case generate high loads on restraints.

Also the pipe is evaluated in the full range of temp., this is:

L1:WNC+T1 (OPE) [max. temp. of the pipe without content]
L2:WNC+T2 (OPE) [min. temp. of the pipe without content]
L3:L1-L2 (EXP) [full range expansion code compliance check]

Regards.
JP.