How to properly install aluminum alloy pipelines to ensure safe usage?

# How to Install Aluminum Alloy Pipelines Correctly to Ensure Safe Operation Aluminum alloy pipelines are widely used in water supply and drainage, HVAC, gas, and industrial fluid transportation due to their light weight, corrosion resistance, and excellent thermal conductivity. Improper installation, however, can easily lead to potential safety hazards such as leakage and rupture. Therefore, standard procedures must be strictly followed. This article details the key points for safe installation of aluminum alloy pipelines in terms of material control, installation operations, quality inspection, and maintenance. ## I. Preparations: Strict Selection of Materials and Tools ### 1. Material Selection - **Pipes**: Prioritize 6061-T6 or 6063-T5 aluminum alloy pipes complying with GB/T 18997.1-2003. The surface shall have a uniform anodic oxide coating (thickness ≥ 10μm) without scratches, deformation, or peeling of the oxide film. - **Fittings**: Joints, valves, and pipe clamps must be compatible with the pipe material (avoid direct contact between aluminum alloy and copper/iron to prevent electrochemical corrosion). Matching products of the same brand are preferred to ensure dimensional consistency. - **Qualification Verification**: Check product certificates and test reports to confirm that the pipe tensile strength is ≥ 200MPa, elongation ≥ 8%, and meets pressure requirements. ### 2. Tool Preparation - **Cutting tools**: Special aluminum alloy pipe cutters (grinder cutting is prohibited to avoid damaging the oxide layer); - **Connecting tools**: Special crimping tools (pressure-calibrated for matching pipe diameters), argon arc welders (for welding); - **Auxiliary tools**: Degreaser (for oil removal), sandpaper (for grinding cuts), level (to ensure pipeline straightness), pressure tester (for pressure testing). ## II. Installation Process: Standardized Operations to Eliminate Hazards ### 1. Pipeline Planning and Measurement - Determine the layout according to design drawings, avoiding heat sources (e.g., boilers, water heaters), power supplies, and mechanical impact areas; - Maintain a clearance of ≥ 15mm for horizontal pipelines and ≥ 20mm for vertical pipelines from walls for later maintenance; - Mark cutting positions and reserve expansion allowance (the thermal expansion coefficient of aluminum alloy is approximately 23×10⁻⁶/℃; expansion joints shall be installed for long pipelines). ### 2. Cutting and Cleaning - Cut vertically with a pipe cutter to ensure flat, burr-free cuts; - Grind cut edges smooth with sandpaper, then wipe the surface with degreaser to remove aluminum chips and grease and prevent seal failure. ### 3. Connection Technology - **Crimp Connection (Recommended)**:  1. Insert the pipe into the crimp fitting to the marked line (ensure full insertion);  2. Crimp with a crimping tool at the manufacturer-specified pressure (e.g., ≥ 12MPa for DN20 pipes), with uniform, crack-free crimp marks;  3. Check for "double-ring" crimp marks at the joint to confirm a secure connection. - **Argon Arc Welding**:  1. Clean the oxide film at the joint and protect with argon gas (flow rate 5–8L/min);  2. Control welding temperature at 600–650℃ to avoid pipe deformation caused by overheating;  3. Cool to room temperature after welding and inspect welds for porosity and slag inclusions. ### 4. Fixing and Support - Use special aluminum alloy pipe clamps, with spacing of 1.5–2m for horizontal pipes and 2m for vertical pipes; - Add pipe clamps within 150mm on both sides of bends and joints to prevent pipeline vibration; - Install rubber gaskets between pipe clamps and pipelines to avoid stress concentration from hard contact. ## III. Quality Inspection: Pressure Testing and Acceptance ### 1. Pressure Testing - **Hydrostatic Test**: 1.5 times the working pressure (no less than 0.6MPa), hold pressure for 30 minutes with no pressure gauge drop and no joint leakage; - **Pneumatic Test**: Applicable to gas pipelines, pressure ≤ 0.6MPa. Check for leaks with soapy water; no bubbles indicate qualification. ### 2. Visual Acceptance - Pipelines are straight without distortion; - Pipe clamps are firmly fixed and joints are not loose; - Surface is undamaged and the oxide layer is intact. ## IV. Corrosion Protection and Maintenance: Extend Service Life and Ensure Safety ### 1. Anti-Corrosion Measures - Coat pipelines with epoxy resin anti-corrosion paint in humid environments; - Install insulating gaskets at contact points of dissimilar metals (e.g., between aluminum alloy and copper valves) to block electrochemical corrosion; - Insulated pipelines shall be equipped with moisture barriers to prevent condensate erosion. ### 2. Regular Maintenance - Check pipe clamps for looseness and joints for leakage monthly; - Conduct a pressure retest annually; - Immediately shut down for maintenance and replace damaged components if corrosion, deformation, or leakage is found. ## V. Safety Operation Notes - Installers must hold valid certificates and be familiar with aluminum alloy pipeline installation specifications; - Wear protective gloves during cutting and fasten safety belts for aerial work; - Stay away from the test area during pressure testing to prevent injury from pipeline rupture; - Avoid open-flame operations near pipelines to prevent high-temperature deformation of aluminum alloy. Safe installation of aluminum alloy pipelines is the foundation for stable system operation. Strict compliance with specifications from material selection to installation acceptance can effectively avoid safety accidents and ensure long-term reliable use of pipelines.