Abstract: This paper introduces the structure, characteristics, main raw materials, economy and market applications of thermal insulation plastic pipelines, which are mainly used to replace the steel pipelines in the centralized secondary network for district heating systems. The caliber of these pipelines usually has a diameter lower than 400 mm and is used at a temperature lower than 80 ℃. By reviewing the use of raw materials, application process and industry development of thermal insulation pipelines, the paper summarized the new development of the plastic pipelines. The thermal insulation plastic pipelines are expected to be applied for the primary heating pipe network, steam transportation, thermal insulation and high-pressure transportation.

Key words: thermal insulation plastic pipelines, heat resistance, pressure resistance, technology; development