By making a circular repetition of an arc of a circle (center, the center of your tube and radius Ø/2) by placing the first arc at one end and measuring the angle to the point of arrival you can make something that looks like circular weld bead (see attachment).
In SW 2015 it becomes very easy to do this because it is now possible to use a single edge to make welds (welding on the edge of the opening of a ferrule for example).
@Frédéric: I want to master the solder aspect tool to know its limits.
@BEB: indeed, I have a closed outline but the rib passes in front of the weld, hence the fact that I want a particular representation since SW does not hide the non-visible part of the weld.
@Coyote: thanks for the info! So I'm waiting for the SW2015 version to be released to see if I can do it better.