Steel-clad steel thermal insulation pipes are classified into two types based on the sliding method: internal sliding and external sliding. 1. Internal sliding: The thermal insulation structure consists of working steel pipe, aluminum silicate, drag-reduction layer, micro-porous calcium silicate, insulation layer, stainless steel reinforcing steel strip, aluminum foil reflective layer, polyurethane insulation layer, outer steel pipe, and external anti-corrosion layer (basically not used anymore).

2. External Sliding Type: Insulating structure consists of working steel pipe, glass wool thermal insulation layer, aluminum foil reflective layer, stainless steel fastening belt, sliding guide bracket, air insulation layer, outer protective steel pipe, and outer anticorrosion layer.