Pipe and Pipeline PU Insulation Solution
High-pressure pipe-in-pipe polyurethane injection lines engineered for district chilled-water and industrial process piping, delivering void-free insulation and zero pipe corrosion.
Precision Pipe-in-Pipe Polyurethane Injection Solutions for District Energy & Process Lines
District cooling networks, chilled-water HVAC loops, and chemical process pipelines suffer from extreme energy drift and accelerated external pipe corrosion when insulated with legacy fiberglass wraps or open-cell elastomeric rubber. Trapped groundwater in buried trenches causes catastrophic outer wall rust pitting, leading to unpredicted fluid leaks. Haifeng’s pipe-in-pipe polyurethane insulation solution injects high-density closed-cell polyisocyanurate formulations directly into the annular gap between the carrier steel pipe and an outer high-density polyethylene (HDPE) jacket. Bonding aggressively to both substrates under in-mold expansion pressure, the monolithic core creates a rugged "three-in-one" composite pipe that handles heavy soil shear loads and eliminates moisture intrusion.
"Three-in-One" Structural Cohesion (EN 253)
Achieves axial shear strength ≥0.12 MPa between steel, foam, and HDPE casing, allowing direct-buried installation without auxiliary expansion loops.
100% Groundwater Moisture Barrier
A 95%+ closed-cell microcellular core prevents capillary moisture tracking, stopping subterranean pipe rust even in saturated high-water-table soils.
Haifeng delivers complete automated pipe manufacturing installations—from high-pressure metering units and dynamic tilt injection heads to pipe end sealing clamps—enabling pipe prefabricators to deliver certified district cooling piping. Haifeng provides equipment and process integration, on-site commissioning and operator training, a 1-year machine warranty and long-term spare parts support. Site construction and material supply follow the project delivery scope.
Production Workflow for Pipe & Pipeline Polyurethane Insulation Line
The workflow for Pipe & Pipeline Polyurethane Insulation Line covers Pipe Centering, Flange Sealing, Annular Injection, Core Solidification. Confirm the sequence and equipment interfaces against the selected material system and product design.
Steel Pipe Shot-Blasting & Casing Centering
Steel pipes are blasted to Sa 2.5; snap-on plastic centering spiders are attached to center the steel pipe precisely inside the outer HDPE casing pipe.
Pipe End Flange Clamping & Venting Setup
Pneumatic or hydraulic end-sealing flanges clamp onto both ends of the pipe assembly, sealing the annular gap while providing micro-perforated air-venting channels.
High-Pressure Annular Cavity Injection
An L-shaped impingement mixing head docks with the central injection port; servo displacement pumps inject liquid precursors at up to 180 bar within 3–8 seconds.
Technical Specifications
Configuration and application values from the supplied engineering brief. Material properties and project results apply to their stated conditions.
| Technical Parameter | Standard Specification / Value | Engineering Context & Verification |
|---|---|---|
| Target Application | District Chilled-Water Lines, Chemical Process Piping | Underground direct-buried & overhead pipelines |
| Material Matrix | Rigid Polyurethane Foam (PUR / PIR) | High-strength structural piping insulation |
| Applicable Pipe Diameters | DN50 to DN1200 (2 Inch to 48 Inch) | Small building risers to giant district trunks |
| Core Foam Density | 60 – 80 kg/m³ | High compressive and axial shear capability |
| Thermal Conductivity (λ) | ≤0.024 – 0.026 W/(m·K) | EN 253 European standard compliance |
| Axial Shear Strength | ≥0.12 MPa (At 23°C and 140°C) | Prevents pipe slipping during thermal expansion |
| Proportioner Fluid Output | 30 – 80 kg/min | High-output capability for large annular volumes |
Pipe Insulation Equipment and Application Views
The equipment views and application illustrations show workshop equipment, pipe handling, storage and transport. Application views do not identify a specific customer delivery or verify foam properties, jacket material or coating chemistry.
Pipe-Insulation Equipment — Liaoning Workshop Views
Pipe Manufacturing and Handling Illustrations
More pipe workshop and handling illustrations
Additional Application Views
Pipe workshop equipment views and layered-pipe schematics show handling, material conditioning and pipe construction. Schematic layers describe application concepts; specific equipment duties and material properties follow the project configuration.
Pipe Workshop and Structure Views
Reference Haifeng Insulation Equipment
Listed equipment shows its current application configuration. The metering unit, hose, gun or injection head and optional modules are selected for this project.
Key Engineering Advantages
Application-specific process controls, tooling and equipment integration.
Zero Ground Water Ingress
Seamless closed-cell core prevents water tracking, stopping pipe rust pitting in direct-buried applications.
Minimal Chilled-Water Thermal Drift
Superior insulation (λ ≤ 0.024) maintains chilled water temperatures across multi-kilometer transmission lines.
Rugged "Three-in-One" Cohesion
High axial shear strength bonds steel, foam, and HDPE, absorbing thermal expansion ground friction.
3× Faster Fabrication Cadence
Automated pipe-in-pipe high-pressure injection slashes manufacturing time compared to manual wrap installation.
Related Equipment Delivery and Application Cases
Review two supplied cases, their equipment delivery, implementation and application results.
District Chilled-Water Pipe PU Insulation Project in Liaoning, China
Chemical Process Pipe PU Line Project in Argentina
Frequently Asked Questions
Process selection, site conditions and equipment integration.
How does this system ensure the foam fills the entire 12-meter pipe length?
What is the significance of the EN 253 axial shear test?
Can this line insulate large-diameter pipes up to DN1200?
What is the typical installation and commissioning timeline on-site?
Discuss Your Insulation Equipment and Application
For Pipe & Pipeline Polyurethane Insulation Line, send finished-product drawings or samples, material data, target output, automation needs and factory conditions. Haifeng can use these inputs to discuss the line configuration and technical interfaces.
