Method for connecting two sections of a district heating conduit

摘要

A heat carrier is guided by a steel pipe (2). A tubular casing (3) is equipped with a thermoplastic material for wrapping a heat insulation section (4) and a thermoplastic connecting sleeve (5). Strips (8) and expanded metal interconnect are used as an insert (6) before pushing connecting sleeve onto casing. The ends of casing are welded at sleeve by electrically heating the insert. Welding conditions are set to heat the external induction coils (7) by providing hooked end portions overlapping in circumferential direction, and with connecting sleeve at casing. An independent claim is included for metallic insert for welding thermoplastic jacket tubes of two mutually welded steel tubes of district heating pipe with thermoplastic connecting sleeve.