In my pass life I work as a Maint. Engr on two sulphur units abd the jacketed transfer lines were a problem. To help keep good hot steam in each section, we ran a common steam and condensate lines parallel to the sulphur line. I had good hot steam going into each section of jacketed line and had a good steam trap on each section. This keep the line hot and helped solve the problem of the steam cutting onto the inter line.