Our professional PUR spary HDPE wrapping steel pipe thermal insulation production line is independently engineered by Huashida for manufacturing large-diameter pre-insulated steel pipes ranging from 508mm to 1620mm. This all-in-one polyurethane foam insulation pipe machine combines three core functional modules: steel pipe external shot blasting derusting unit, continuous polyurethane spray foaming system and HDPE strip wrapping production section for complete buried district heating pipe fabrication.

As premium patented Thermal insulation pipe manufacturing equipment, the whole set owns multiple national utility patents, third-party Level 5 technology certification and Shandong Provincial First Set of Technical Equipment accreditation, complying with top domestic industrial standards for large diameter pre-insulated pipeline production.

Adopting continuous automatic PUR spray technology, this fully PLC-controlled pre-insulated steel pipe production line boosts overall output while cutting raw material and power wastage. It forms stable three-layer trinity composite structure (steel pipe + PU foam insulation + HDPE outer jacket) with high closed-cell foam rate and low water absorption. Finished eco-friendly low-carbon polyurethane insulated steel pipes hold consistent insulation performance for underground heating pipeline projects.

Production Process

• Steel pipe surface shot blasting & full derusting
• Medium-frequency induction preheating for uniform PU bonding
• Precise automatic polyurethane spray foaming
• HDPE strip wrapping around solid PU insulation layer
• Finished insulated pipe end trimming

Production steps:

1. Rust removal on the outer wall of the steel pipe
2. After rust removal, the steel pipe is lifted to the pipeline rack - it is transported to the spraying conveyor line by a pipe transport cart - the steel pipe is heated - polyurethane spraying - it is transported to the storage platform by a lifting cart - PE layer winding - water spray cooling - connection incision - finished pipe offline - finished pipe inspection - port repair - spray code packaging offline

Features

1. Dust removal meets environmental standards

   By adopting an intelligent shot blasting and rust removal scheme, the equipment can be opened sequentially and self locked, the shot blasting motor can save energy through frequency conversion, the sand volume can be set according to the pipe diameter, the air washing system can clean the shot sand, and the plug type can quickly change specifications. The three-level dust removal meets environmental protection standards.

2. Suitable for the production of large-diameter insulation pipes

   By adopting a high load-bearing spiral conveyor line, the polyurethane foam spraying and polyethylene winding processes are continuously carried out, which has the advantages of high efficiency, energy saving, speed, and stability. It is suitable for the continuous production of large-diameter insulation pipes and saves investment in transportation equipment.

3. Automated operation of production lines

   Realize automatic processing of upper and lower pipes. The conveyor line is equipped with upper pipe sensors, automatic acceleration tracking sensors, automatic acceleration detachment sensors, detachment confirmation sensors, and automatic descent sensors to ensure the automated operation of the production line.

4. Spraying saves materials

   The online spraying speed of pipelines is fast; Constant intermediate frequency power, infrequent on/off, minimal impact on the power grid, balanced temperature, and energy conservation; Continuous spraying saves raw materials, and the head and tail of the steel pipe are automatically connected to ensure consistent surface thickness during spraying.

5. Efficient extrusion of pipelines

   Using efficient and energy-saving extruders for extrusion, and using mechanical clamping devices for winding and compacting; Automatic cutting, triple cutting of anti-corrosion coating, automatic pipe removal during offline production, accelerating detachment.

6. Automated precision machining of pipeline interfaces

   Centralize multiple processing steps on a single device for automated processing, achieving precise control over the size, angle, and blunt edge dimensions of the pipe opening.