1. Structural Form
Pipe: Utilizing new types of working pipes such as PERT, PPR, and PE.
Insulation: Hard polyurethane foam plastic used; Leak alarm line: During the manufacturing of high-temperature pre-fabricated buried thermal insulation pipes, an alarm line is embedded within the insulation layer close to the steel pipe. In the event of a leak at any point in the pipeline, the alarm line transmits the signal, triggering an alert on a dedicated detection instrument, which shows the precise location of the leak and its severity. This allows for quick notification to maintenance personnel to address the leaking section and ensure the safe operation of the thermal network.
External sheath: High-density polyethylene or glass fiber reinforced plastic (GFRP) external sheath.

2. Application Range
Insulation for liquids and gases with temperatures not exceeding 120°C and pressures not exceeding 1.6 Mpa.

3. Standard of Execution
High-Density Polyethylene (HDPE) Outer Sheath Polyurethane Foam Pre-Fabricated Direct-Buried Insulated Pipe (GB/T 29047-2012)
High-Density Polyethylene (HDPE) Outer Sheath Polyurethane Foam Pre-Molded Direct Burial Insulation Pipe (CJ/T 114-2000)
Integrated Pre-fabricated Insulated Pipe System for Underground Geothermal Networks - Insulated pipes composed of a working steel pipe, polyurethane insulation, and polyethylene outer sheath (EN253-2003).

4. Lifespan
Due to the high-density polyethylene sheath of this structure, it boasts excellent waterproofing, moisture-proof, and corrosion-resistant properties. The working pipe and insulation layer are fully protected within the sheath, allowing for continuous use under normal operating conditions for up to 30 years.