When creating a mechanically welded (1/2" copper tube), the developed length is not displayed in evaluated value (Here is the message: "LENGTH@@@Tube Copper 1/2"<6>@Tube 7-8''. SLDPRT")
So, I change the profile with another tube and everything works. So I copy the model of the tube that works, and replace it with my sketch values and it doesn't work anymore again. A mystery, isn't it?