Insulated pipes

Insulated pipe is a piping system with thermal insulation. Its core function is to reduce heat loss during the transport of media (such as hot water, steam, and hot oil) within the pipe while protecting the pipe from environmental influences. It is widely used in building heating, district heating, petrochemicals, municipal engineering, and other fields.

1. Core Structure

Insulated pipe is typically a multi-layer composite structure consisting of three main components:

• Working Steel Pipe: The inner core layer, responsible for transporting the media. Materials typically include seamless steel, galvanized steel, or plastic pipes, and must be pressure-resistant and corrosion-resistant.

• Insulation Layer: The critical middle layer, responsible for thermal insulation. Common materials include polyurethane foam, rock wool, glass wool, and polyethylene. Polyurethane foam is currently the mainstream choice due to its low thermal conductivity and excellent insulation performance.

• Outer Sheath: The outer protective layer protects the insulation layer from moisture, aging, and mechanical damage. Materials typically include high-density polyethylene (HDPE), fiberglass, or an anti-corrosion coating.

II. Main Types and Characteristics

Based on the insulation material and application scenario, common types and characteristics are as follows:

• Polyurethane Insulated Pipe: Thermal conductivity ≤ 0.024 W/(m·K), high insulation efficiency, low-temperature resistance, and aging resistance. Suitable for hot water and steam pipelines with temperatures between -50°C and 120°C, it is the preferred choice for central heating and floor heating systems.

• Rockwool Insulated Pipe: High-temperature resistance (up to 600°C) and a high fire rating (Class A non-combustible), but with high water absorption, it requires moisture-proofing. It is primarily used for industrial high-temperature pipelines (such as boiler steam pipes).

• Glass Wool Insulated Pipe: Lightweight, with excellent sound insulation, and a temperature resistance range of -120°C to 400°C, it is suitable for low-temperature pipelines (such as air conditioning refrigerant pipes) and for insulation of pipes in civil buildings.

III. Core Advantages

1. Energy Saving and Consumption Reduction: Reduces heat loss in the medium, lowering energy consumption in heating, industrial production, and other scenarios. Long-term use can significantly reduce operating costs.

2. Pipeline Protection: The outer sheath protects against water, soil corrosion, and mechanical impact, extending the pipe’s service life and reducing maintenance frequency.

3. Stable Pipeline Operation: Maintains stable medium temperature to prevent temperature fluctuations from affecting operation (e.g., maintaining indoor temperature for heating pipes and ensuring process stability for industrial pipes).

4. Convenient Installation: Some insulated pipes are prefabricated, requiring only on-site connection and installation, shortening the construction period and reducing complexity.

IV. Applicable Applications

• Municipal: Urban centralized heating networks and tap water pipes (to prevent freezing in winter).

• Construction: Floor heating pipes in residential and commercial buildings, and heating and cooling medium pipes for central air conditioning.

• Industrial: Hot oil pipelines in the petroleum and chemical industries, steam pipelines in power plants, and cryogenic medium pipelines in cold chain logistics.