advice on pipe creation

 From:  colinpartridge
Just started use of Moi3d ( on OSX) so feeling my way round a bit. I'm trying to create some pipe elements as here..

What would the best/simplest workflow to achieve the various ridges etc. I thought using the sweep tool and creating a rail that included the ridges would do the trick, but I ended up with an asymmetric result. maybe creating the basic pipe shape and then adding the ridges using booleans would be easiest? I also tried to to add thickness to the surface but failed dismally. Any tips gratefully received.

cheers Colin