Insulation steel pipes are widely used in liquid and gastransmission pipe networks,chemica  pipe insulatiorprojects in petroleum, chemical, central heating andheating networks, central air-conditioning ventilationpipes, and municipal engineering.High-temperatureprefabricated direct-buried thermal insulation steepipe is a direct-buried prefabricated thermal insulationsteel pipe with good thermal insulation performance.safety and reliability, and low construction cost.