FIELD: technological processes.
SUBSTANCE: method includes a concentric pattern of a kelly with centring elements inside a mantle pipe forming a "pipe-in-pipe" structure, sealing the ends of the "pipe-in-pipe" structure with end caps, supplying expandable heat insulating material through a process hole in one of the caps. When the expandable material supply is finished, the process hole in the cap is sealed and the gases, creating excess pressure in an annular cavity, are released through a perforated section of the end cap with a diameter of perforations 0.1÷3.0 mm.
EFFECT: method implementation allows for a reduction of number of process operations, for excluding losses of reactive liquid polyurethane composition from the shell side through process clearances, reduction of end product rejects due to creation of optimum conditions for heat insulation layer formation, provision for stable quality of end products due to production of heat insulated pipes with a design conductivity factor.
11 cl, 7 dwg
