1. Structural Form
Work Fittings: Steel pipe fittings, PERT pipe fittings, PE pipe fittings, etc.
Insulation Material: Rigid polyurethane foam plastic; Leak Alarm Line: During the manufacturing of high-temperature pre-fabricated buried thermal insulation pipes, an alarm line is embedded within the insulation layer adjacent to the steel pipe. Should a leakage occur at any point in the pipeline, the alarm line will transmit the signal, triggering an alarm on a specialized detection instrument. This instrument will display the precise location of the leak and the extent of the leakage, enabling maintenance personnel to promptly address the leaking section and ensure the safe operation of the heating network.
Outer Sheath: High-density polyethylene outer sheath, glass fiber reinforced plastic outer sheath, galvanized iron sheet, etc.

2. Applicable Range
Polyurethane pre-insulated buried pipe fittings are suitable for heating and cooling of liquids and gases at temperatures not exceeding 150°C and pressures not exceeding 2.5Mpa. Steel sleeve steel pre-insulated buried pipe fittings are suitable for heating and cooling of liquids and gases at temperatures not exceeding 350°C and pressures not exceeding 2.5Mpa.

3. Execution Standards
High-Density Polyethylene (HDPE) Outer Sheath Polyurethane Foam Pre-fabricated Direct Burial Insulation Pipe (GB/T 29047-2012)
High-Density Polyethylene Extruded Foam Plastic Pre-Molded Direct-Buried Insulated Pipe (CJ/T 114-2000)
Integrated pre-insulated pipe system for underground hot water networks - Insulating pipes consisting of a working steel pipe, polyurethane insulating layer, and polyethylene outer sheath (EN253-2003).
"Technical Conditions for Prefabricated Direct Burial Steam Insulation Pipes for Urban Heating (CJ/T200-2004)"
"Technical Code for Prefabricated Direct-Buried Steam Pipeline for Urban Heating (CJJ104-2005)"

4. Service Life
The product can be continuously used for 30 years under normal operating conditions.