The Polyurethane (PU) Foaming Machine is an advanced industrial solution designed for manufacturing high-performance pre-insulated steel pipes. This system integrates precise PU foam injection technology with durable PE outer layer wrapping, ensuring superior thermal insulation and long-term corrosion protection.

Widely used in district heating, oil & gas transportation, and chemical pipeline systems, this production line delivers consistent quality, high efficiency, and reliable performance for modern pipeline manufacturing.

• Integrated Production Process - Combines polyurethane foaming and polyethylene wrapping in one continuous, automated system
• High-Precision PU Injection System - Ensures uniform foam density, excellent adhesion, and optimal insulation performance
• Advanced PE Wrapping Technology - Provides a strong, seamless outer protective layer with high resistance to moisture, impact, and environmental stress
• Automated Control System - PLC-based intelligent control for accurate parameter adjustment, stable operation, and reduced labor requirements
• Energy Efficient Design - Optimized system reduces material waste and energy consumption while maximizing output

Rigid polyurethane spraying polyethylene winding prefabricated directly buried insulation pipe consists of steel working pipe, spraying polyurethane rigid foam insulation layer and winding polyethylene outer protective pipe.

1. Steel pipe rust removal - Hydraulic lifter transports steel pipe to conveying line. Shot blasting removes rust and impurities, achieving SA2.5 surface standard
2. Polyurethane spraying - Steel pipe moves at constant speed while spraying robot applies foaming materials evenly. Polyurethane foams quickly to achieve required compressive strength and design thickness
3. Polyethylene pipe winding - Extruder applies molten polyethylene sheet that wraps around the insulation layer, forming protective outer layer
4. Spray cooling - Semi-finished pipe is cooled by online spraying device, completing the insulation bonding
5. Tracking and cutting - Automated system tracks and cuts pipes with high-speed cutting saw, ensuring production continuity and efficiency
6. Numbering and storage - Finished pipes are numbered and moved to warehouse

• Uniform density, thermal conductivity, and compressive strength indices ensure superior overall pipe performance
• Polyurethane foaming perpendicular to pipe axis improves compressive strength of insulation layer
• Strong adhesion between steel pipe surface and polyurethane foam due to high reaction activity of spraying materials
• Rough foam surface enhances bonding between insulation layer and outer HDPE protective layer
• Customizable insulation thickness (15-20mm) provides significant cost savings
• Adjustable polyethylene outer protective layer thickness without additional molds reduces customer costs
• Circumferential winding improves polyethylene protective layer's elongation, tensile strength, and circumferential strength
• Fully automated production ensures consistent quality and improved production speed

Qingdao Huashida Machinery Co., LTD is a manufacturer of series of plastic pipe machines, municipal pipe machines, pipe insulation & anticorrosion machines, and pipe jointing & anticorrosion materials, with more than 20 years of production experience.

• HDPE jacket pipe for pre-insulated pipe Production Line (110-2000mm)
• Rigid pre-insulated pipe Production Line
• Flexible pre-insulated pipe (PERT) production line
• Steel pipe FBE/3LPE/3LPP anti-corrosion coating line
• Steel pipe derusting line
• PE pressure pipe/Water Gas supply pipe production line
• PP/PE plastic board/sheet/geomembrane production line
• NBR PVC Thermal insulation tube/plate production line
• Pipeline anti-corrosion materials and instruments: heat shrink joint coating sleeve, electro-fusion weldable joint sleeve, portable welding gun (extruder), PE PP welding rod

We have been working with more than 400 overseas customers and exporting our products to Kazakhstan, Uzbekistan, Middle East, Russia, Nigeria and other countries.