Pre Insulated Pipe

Published:2025-06-16 | Last Updated: 2025-06-16    Views: 1

In today's construction, industrial, and municipal engineering sectors, pre-insulated pipes are emerging as an increasingly vital solution for efficient thermal insulation.

They are widely used in building heating and cooling systems, effectively reducing energy consumption and improving system efficiency; in the industrial sector, pre-insulated pipes are used for pipeline insulation, ensuring stable medium temperature during transportation and minimizing heat loss; in municipal engineering, they are employed in heating and cooling networks to guarantee the stability and reliability of urban energy supply.

As demands for energy conservation, emissions reduction, and sustainable development continue to rise, the importance of pre-insulated pipes is becoming increasingly evident.

This article will delve into various aspects of pre-insulated pipes, including their definition, characteristics, advantages, application scope, technical parameters, installation, and maintenance. Through a comprehensive overview, readers will gain a better understanding of the performance and applications of pre-insulated pipes, enabling them to make more informed decisions in practical engineering projects.

I. Core Definition of Prefabricated Insulated Pipes

Pre-insulated pipes are composite pipe systems composed of a steel pipe base (including welded steel pipes seamless steel pipes, or spiral steel pipes), a polyurethane foam insulation layer, and a protective outer shell.  

Among these, polyurethane-insulated steel pipes, with an ultra-low thermal conductivity of 0.033 W/m·K, have become the global standard choice. These pipes are pre-fabricated in factories and installed directly on-site, significantly reducing engineering complexity.  

II. Technical Features of Insulated Steel Pipes

(1) Triple Protection Structure  

Pressure-bearing layer: Welded steel pipe/seamless steel pipe (DN50–DN1200) capable of withstanding 6 MPa pressure  

Insulation layer: 60 kg/m³ high-density polyurethane foam-insulated steel pipe with a closed-cell rate >92%  

Protective layer: HDPE or fiberglass shell resistant to UV rays and corrosion  

(2) Excellent Thermal Performance

Polyurethane foam insulated steel pipes under -50°C to 150°C operating conditions:  

Heat loss is only 1/10 of that of bare pipes  

Temperature drop per kilometer <0.5°C (hot water transportation)  

(3) Intelligent Adaptive Design

III. Analysis of the Four Core Advantages

(1) Energy Efficiency and Cost Savings

Directly buried polyurethane-insulated steel pipes reduce heat loss by 40%. Based on a 10-kilometer heating network:  

Annual coal savings ≈ 1,200 tons  

Payback period < 3 years  

(2) Ultra-Long Service Life

Cathodic protection combined with three-layer corrosion protection extends the service life of insulated steel pipes to over 50 years (EN 253 certified), doubling the lifespan of traditional pipes.

(3) Installation Revolution

Direct burial installation technology revolutionizes the pipeline corridor model:  

Construction efficiency improved by 60%  

Earthwork volume reduced by 50%  

Earthquake displacement resistance up to 30mm  

(4) Environmental Friendliness

The carbon emissions during the production process of polyurethane foam insulated steel pipes are 65% lower than those of rock wool pipes, and waste materials can be recycled and reused.

IV. Insulated Steel Pipe Technical Specifications

Operating Temperature Range: e.g., -100°C to 150°C.  

Thermal Conductivity: e.g., 0.016–0.027 W/(m·K).  

Density: e.g., insulation layer density 60–80 kg/m³.  

Compressive Strength: e.g., ≥0.3 MPa.  

Water Absorption Rate: e.g., ≤0.2 kg/m².

Dimension Specifications: such as pipe diameter range DN20 to DN1200, length 6 meters or 12 meters.

V. Application Areas of Prefabricated Insulated Pipes

(1) Construction Industry  

Heating Systems: Used for central heating pipelines in residential and commercial buildings.  

Cooling Systems: Used for chilled water pipelines in central air conditioning systems.  

(2) Municipal Engineering  

Urban Heating Networks: Used for central heating pipelines.  

Water Supply and Drainage: Prevent pipeline freezing at low temperatures to ensure the normal operation of municipal water supply and drainage systems.  

(3) Industrial Sector

Petrochemical Industry: Used for pipelines transporting petroleum, natural gas, and other media.  

Chemical Pipelines: Used for transporting high-temperature or low-temperature media.  

(4) Energy Sector

Combined Heat and Power (CHP): Used for conveying hot water or steam to reduce heat loss.  

New Energy: Used for pipeline engineering projects supporting new energy projects such as wind power and photovoltaic systems.  

(5) Other Fields  

Cold Storage Construction: Used for conveying low-temperature media in cold storage facilities.  

Industrial Steam Conveyance: Used for steam pipelines to reduce heat loss and improve steam utilization efficiency.

VI. Comparison between prefabricated insulated pipes and ordinary insulated pipes