1. Structural Form
Pipe: Seamless steel pipe, spiral steel pipe, stainless steel pipe, welded pipe, galvanized pipe, etc.
Insulation material: rigid polyurethane foam.
Leakage Alarm Line: During the manufacturing of high-temperature pre-fabricated buried insulation pipes, an alarm line is embedded in the insulation layer adjacent to the steel pipe. In the event of a leakage at any point in the pipeline, the alarm line transmits the signal, triggering an alarm on a dedicated detection instrument and displaying the exact location and severity of the leakage. This allows for prompt notification to maintenance personnel to quickly address the leaking section and ensure the safe operation of the heating network.
Outer protective tube: Galvanized iron sheet, aluminum sheet, stainless steel, etc.

2. Application Scope
Insulation for liquids and gases at temperatures not exceeding 150°C and pressures not exceeding 2.5 MPa.

3. Standard Execution: "High-Density Polyethylene Outer Sheath Polyurethane Foam Plastic Pre-fabricated Direct Burial Insulation Pipe" (GB/T 29047-2012); "High-Density Polyethylene Outer Sheath Polyurethane Foam Plastic Pre-fabricated Direct Burial Insulation Pipe" (CJ/T 114-2000); "Integral Pre-fabricated Insulation Pipe System for Underground Geothermal Network - Insulation Pipe Comprising a Working Steel Pipe, Polyurethane Insulation Layer, and Polyethylene Outer Sheath" (EN253-2003)

4. Service Life
The thermal insulation pipe in this structure is a three-layer design, with the working pipe and insulation fully protected by the outer sheath; the outer sheath is coated with galvanized corrosion protection, allowing for continuous use under normal operating conditions for up to 30 years.