The retrospective pulling in of smooth tubes into protective pipes at construction sites is very time and money consuming, especially with longer duct lines. Due to that, more and more customers use pre-assembled products to increase the productivity at the construction site. MAINCOR automatically pulls the pipe into a protective tube and saves an entire assembly step as well as time and money for the customer during laying. With the pipe-in-pipe-service offered by MAINCOR, pipes with a length of up to 200 meters can be assembled.