Aluminum alloy plastic-lined composite pipe for water supply in residential building heating systems, PPR cold and hot water pipes.

Introduction to Aluminum Alloy Lined Plastic Composite Pipe
I. Definition and Structural Characteristics
Aluminum alloy lined plastic composite pipe is a new type of pipeline that combines the advantages of metal and plastic. It consists of an outer aluminum alloy tube and an inner thermoplastic plastic tube (such as PPR, PERT, PB) tightly bonded through prestressed composite technology.
Outer layer: Made of 6063 deformed aluminum alloy, seamlessly extruded and anodized (oxide film thickness ≥10μm), featuring high strength, corrosion resistance, and UV resistance.
Inner layer: Food-grade thermoplastic plastic, ensuring water safety, hygiene, and non-toxicity, with low thermal conductivity and aging resistance.
Composite technology: Optimizes interlayer bonding strength through physical prestressing, reducing the overall expansion coefficient to just 1/5 that of pure plastic pipes, addressing the issues of easy deformation and impact sensitivity in plastic pipes.
II. Technical Advantages
Oxygen barrier and anti-permeability: The aluminum alloy layer completely blocks oxygen infiltration, inhibiting microbial growth and extending pipeline lifespan.
Lightweight and high strength: Weighs only 1/6 of galvanized pipes but offers higher compressive strength, suitable for exposed or complex environments.
Thermal insulation and energy efficiency: Low thermal conductivity reduces heat loss, with excellent insulation performance.
Corrosion resistance: Outer anodized treatment adapts to humid or chemically corrosive environments.
Easy installation: Heat fusion connection eliminates threading, simplifying operation and reducing construction costs.
Hygienic and safe: Inner plastic meets food-grade standards, non-toxic and harmless.
III. Application Scenarios
Construction field: Domestic cold and hot water, heating, and air conditioning pipelines, especially suitable for high-end residences, hotels, hospitals, etc.
Industrial field: Chemical fluid transport, gas pipelines (requires chemical resistance adaptation).
Special scenarios: Solar heating systems, underfloor heating, fire pipelines, supporting operating environments from -20°C to 95°C.
IV. Key Construction Process Points
Connection method: Heat fusion or electrofusion, requiring specialized tools (constant temperature 260°C heat fusion machine).
Installation environment: When operating temperature is below 5°C, extend heating time to avoid rapid cooling causing leaks.
Fixation spacing: Adjust support spacing for vertical and horizontal pipes based on pipe diameter (typically 500-1300mm), with increased fixation at bends.
Acceptance standards: Hydrostatic test pressure at 1.5 times working pressure, stable for 1 hour without leakage.
V. National Standards and Specifications
Implementation standards: GB/T41494-2022, specifying material, structure, connection methods, and performance requirements.
Key indicators: Liner pipe must withstand 1.6MPa pressure, ensuring 50-year service life; oxygen barrier and impact resistance pass strict tests.
VI. Market Status and Development Trends
Market size: Global market projected to reach $17.5 billion by 2030, with a CAGR of approximately 6.5%.
China's demand in 2023 was 14,300 kilometers, with a CAGR of 2.35%, mainly applied in building water supply and HVAC fields.
Driving factors: Environmental needs: Aluminum alloy is recyclable, and inner plastic tubes use eco-friendly materials, aligning with green building trends.
Policy push: National environmental standards are rising, promoting the upgrade and replacement of traditional plastic pipes.
Future trends: Technological upgrades: Improve bending performance to adapt to more complex installation scenarios.
Application expansion: Extend to industrial fluid transport and municipal pipeline networks, replacing traditional metal or pure plastic pipes.
VII. Challenges and Improvement Directions
Higher cost: Reduce costs through scaled production and process optimization.
Bending limitations: Develop new composite technologies to enhance bending flexibility.
Intensified market competition: Companies need to strengthen brand building and technological innovation, improving service quality.