Insulated steel pipe is a steel pipe that is processed by the heat preservation process and ensures that the internal temperature and surface temperature of the working steel pipe meet or meet the requirements of use under the effect of different working environments and external media.

Insulation pipelines are widely used in liquid and gas transportation pipeline networks, chemical pipeline insulation engineering petroleum, chemical industry, central heating heating network, central air conditioning ventilation pipelines, municipal engineering, etc.

The high-temperature prefabricated direct-buried thermal insulation pipe is a direct-buried prefabricated thermal insulation pipe with good thermal insulation performance, stability and reliability, and low engineering cost. It effectively solves the problems of insulation, sliding lubrication and waterproofing of exposed pipe ends of prefabricated direct buried insulation pipes for high-temperature heat transmission at 130℃~600℃ in urban central heating. The high-temperature prefabricated directly buried insulation pipe not only has the advanced technology and practical performance that traditional trenches and overhead laying pipes are incomparable, but also has significant social and economic benefits. It is also a powerful measure for heating and energy saving. The high-temperature prefabricated direct-buried insulation pipe adopts the direct-buried heating pipeline technology, which indicates that the development of China's heating pipeline technology has entered a new starting point.

The heat preservation tube is composed of a steel tube, a glass fiber reinforced plastic inner sheath, and a glass fiber reinforced plastic shell, and is characterized in that it also includes a high-temperature heat-insulation insulation layer, a lubrication layer, and an elastic seal.