City Suburban Heating Network Expansion Project

To support urban expansion and meet the high central heating demand in Sofia, Bulgaria, the municipal heating utility extended its primary piping network into newly built residential suburbs. Sanjie Pipe Mart successfully delivered DN300 Pre-insulated Polyurethane Pipes and corresponding butt-fusion joint materials in compliance with European EN 253 and EN 12201 standards.

These pipes utilize food-grade high-performance polyurethane insulation materials and standard-compliant HDPE outer protective jackets. During construction, certified joint-welding techniques were implemented to establish secure, continuous, and leak-free insulation joints. The pre-insulated pipe system effectively maintains hot water flow temperatures over long distances, drastically reducing heating costs and lowering carbon emissions for European green building projects.