For cities of Northern and Northeastern regions of Russian Federation located in harsh climatic conditions it is necessary to modernize the heat networks intensively to ensure economic efficiency and reliability of heat supply. The heating pipes with polyurethane foam insulation have a considerable advantage in comparison with other types of thermal insulation constructions; this is showed by service experience of existing heating systems.

The article is about the analysis of the energy efficiency of increase the thickness of the insulating covering of heat pipes of the heat main line projected from the Apatity heat electropower station to the central heat station in the town Kirovsk of Murmansk region.

The heat losses will decrease on 33 % in case of the use of steel pipes GOST 30732-2006 with thickened polyurethane foam insulation (with the carbon dioxide blowing). The heat losses will decrease on 7,3 Gkal/y. (7,8 millions of rubles in monetary terms in 2011 year) with increasing thickness of the insulation on 50 mm (from 85 mm to 135 mm).