Differences Between “Steel-Sleeved Steel” and “Plastic-Sleeved Steel” Structures in Insulated Steel Pipes

Differences Between “Steel-Sleeved Steel” and “Plastic-Sleeved Steel” Structures in Insulated Steel Pipes

1. Outer Jacket Material

• Steel-Sleeved Steel pipes have an outer protective layer made of steel.

• Plastic-Sleeved Steel pipes use a plastic outer jacket, typically made from materials like high-density polyethylene (HDPE).

2. Corrosion Resistance

• The steel outer jacket in Steel-Sleeved Steel pipes offers strong mechanical protection but requires additional anti-corrosion coatings to prevent rust and degradation.

• The plastic jacket in Plastic-Sleeved Steel pipes provides inherent corrosion resistance due to its chemical inertness and waterproof nature, reducing the need for extra coatings.

3. Mechanical Strength

• Steel-Sleeved Steel pipes deliver higher mechanical strength and superior impact resistance, making them suitable for harsh environments with heavy loads or abrasive soil conditions.

• Plastic-Sleeved Steel pipes have relatively lower mechanical strength but offer flexibility and resistance to cracking under certain conditions.

4. Thermal Insulation

• Both structures include an insulation layer, commonly polyurethane foam, between the inner steel pipe and the outer jacket.

• The choice of outer jacket (steel or plastic) does not significantly affect the insulation’s thermal performance but influences durability and suitability for different environments.

5. Installation and Handling

• Steel-Sleeved Steel pipes are heavier, requiring careful handling, welding for joints, and more labor-intensive installation processes.

• Plastic-Sleeved Steel pipes are lighter and easier to transport, with joints commonly made using heat fusion methods, simplifying installation.

6. Typical Applications

• Steel-Sleeved Steel pipes are preferred in applications demanding high mechanical protection, such as long-distance pipelines buried underground under heavy soil pressure or rocky terrain.

• Plastic-Sleeved Steel pipes are commonly used where corrosion resistance and ease of installation are priorities, such as in municipal heating and cooling networks or less mechanically demanding environments.

Summary

In essence, Steel-Sleeved Steel pipes emphasize mechanical strength and impact resistance but need additional corrosion protection, while Plastic-Sleeved Steel pipes prioritize corrosion resistance and easier installation with moderate mechanical protection. The selection depends on project-specific requirements including environmental conditions, mechanical stresses, and installation logistics.