Standard Mechanical Works QA/QC Site Inspection Checklist

⚙️ Standard Mechanical Works QA/QC Inspection Checklist

General Quality Assurance & Quality Control Protocol for Mechanical Building Services Execution

📌 Stage-I: Pre-Execution & Material Approval Stage

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  Sample & Brand Approval: Verify that all mechanical equipment (Chillers, AHUs, Pumps, Valves) have approved samples and datasheets from project consultants. Standard Specs
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  Factory Acceptance Test (FAT): Verify Manufacturer Test Certificates (MTC) and factory testing reports for major plant equipment prior to site dispatch.
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  Approved Coordination Drawings: Ensure Composite Combined Services Drawings (HVAC ducting, piping, fire protection) are fully coordinated before installation. Design Norms
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  Storage & Handling: Confirm pipes, valves, and insulation materials are stored on raised wooden sleepers above ground and protected against weather and moisture.

❄️ Stage-II: HVAC System QA/QC Inspection

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  Duct Fabrication & Sheet Gauge: Inspect Galvanized Iron (G.I.) sheet gauges, zinc coating, and flange connections as per approved duct construction standards. Standard HVAC Specs
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  Duct Leakage Testing: Perform duct leakage and pressure testing prior to applying thermal or acoustic insulation.
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  Chilled Water Piping Hydro-test: Test chilled water lines at 1.5 times working pressure (minimum 10 kg/cm²) for 24 continuous hours. Piping Specs
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  Vibration Isolation & Dampers: Ensure AHUs and Chillers rest on anti-vibration rubber pads/spring isolators, and motorized fire dampers interlock with the central BMS/Alarm panel.

🧯 Stage-III: Fire Protection & Sprinkler System

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  Pipe Material Verification: Inspect heavy/medium class steel piping for wet riser mains and sprinkler networks. Material Standards
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  Welding Quality & Testing: Conduct visual inspections and random dye penetrant testing (DPT) on critical welded joints.
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  Hydraulic Pressure Test: Hydro-test the fire fighting pipe network at 1.5 times working pressure for a minimum of 24 hours without pressure loss. Fire Safety Standards
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  Sprinkler Spacing & Clearance: Verify coverage area per sprinkler head and ensure proper deflector clearance from ceilings.
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  Fire Pump Automation: Calibrate auto-cut-in and auto-cut-off pressure switches for Jockey Pumps, Main Electric Pumps, and Standby Diesel Pumps.

🚰 Stage-IV: STP, WTP & Pumping Equipment

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  Pump Alignment & Grouting: Verify dial-gauge alignment of pump-motor couplings and proper non-shrink epoxy grouting.
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  STP Aeration Grid Leveling: Check levelness of bubble diffusers in aeration tanks and pressure relief valves on air blowers.
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  Pressure Tank Pre-charge: Inspect bladder pre-charge pressure in hydro-pneumatic vessels and pressure transducer responsiveness.

🛠️ Stage-V: Testing, Adjusting, Balancing (TAB) & Handover

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  Air & Water Balancing: Verify airflow (CFM) at air diffusers and water flow (GPM/LPS) using calibrated balancing valves and meters.
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  Noise Level Measurement: Measure decibel levels in plant rooms and occupied spaces to ensure compliance with acoustic comfort criteria.
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  As-Built Drawings & Handover: Compile signed Testing & Commissioning (T&C) sheets, As-Built drawings, and Operation & Maintenance (O&M) manuals for project handover.

💡 General Engineering Note: This checklist provides standard Quality Assurance (QA) and Quality Control (QC) parameters commonly followed in modern MEP construction projects for mechanical building services.