A Polyurethane Insulated Pipe (also known as PU Foam Insulated Pipe or Pre-insulated Steel Pipe) is a type of pipeline system designed to reduce heat loss during the transportation of hot or cold media.
It is widely used in district heating systems, oil and gas pipelines, chemical industries, and HVAC systems because of its excellent insulation performance and long service life.
A typical polyurethane insulated pipe consists of three layers: the steel working pipe, the polyurethane insulation layer, and the outer protective jacket.
Structure of Polyurethane Insulated Pipes
1. Steel Working Pipe
The steel pipe is the inner pipe used to transport the medium such as hot water, steam, oil, or gas.
Common materials include:
Carbon steel pipe (ASTM A106 / ASTM A53)
Seamless steel pipe
API pipeline steel
Q235B or equivalent steel grades
The selection of the working pipe depends on pressure, temperature, and transported medium.
2. Polyurethane Foam Insulation Layer
The middle layer is rigid polyurethane foam, which is one of the best insulation materials available today.
Main characteristics include:
Low thermal conductivity (0.022–0.033 W/m·K)
High insulation efficiency
Strong adhesion to steel pipe
Long-term thermal stability
This insulation layer significantly reduces energy loss during heat transmission.
3. Outer Protective Jacket
The outer protective layer protects the insulation from moisture, corrosion, and mechanical damage.
Common outer jacket materials include:
HDPE (High-Density Polyethylene) jacket
FRP (Fiberglass Reinforced Plastic) jacket
Steel casing
Among them, HDPE jacketed polyurethane insulated pipes are the most widely used in district heating systems.
Applications of Polyurethane Insulated Pipes
Polyurethane insulated pipes are widely used in many industries, including:
District heating pipelines
Hot water transportation systems
Steam pipelines
Oil and gas industry
Chemical processing plants
HVAC chilled water systems
Industrial thermal pipelines
Because of their high insulation performance, these pipes play an important role in energy-saving pipeline systems.
Tags: polyurethane insulated steel pipe, HDPE jacketed insulated pipe, underground insulated pipe system,
