Zn-Al-Mg carbon steel PV brackets matched with stainless steel bolts suffer galvanic corrosion under long-term high chloride sea wind exposure. Rust and salt scale fill thread gaps and cause thread seizure. Forcible disassembly with regular wrenches easily breaks bolts and scrapes bracket profiles, replacement cost of single tidal flat bracket group reaches thousands RMB. Standardized disassembly & repair craft greatly cuts operation maintenance cost.
| Disassembly Tool Type | Applicable Seizure Degree | Operation Time Per Bolt | Bracket Profile Damage Risk | Applicable PV Scenarios |
| Penetrating Rust Remover + Extended Torque Wrench | Light surface rust & slight seizure | 8-12 mins per bolt | Nearly zero damage | Inland & mild coastal distributed PV routine maintenance |
| Hydraulic Separate Puller Disassembly Tool | Medium rust seizure, intact threads | 15-20 mins per bolt | Controllable, rare scratch on profile | Riverside & within 5km coastal PV tracker overhaul |
| High-temperature Hot Air Gun Heating Disassembly | Heavy salt scale seizure, uncorroded thread core | 20-25 mins per bolt | High heat damages Zn-Al-Mg coating on bracket surface | Tidal flat PV with spare uncoated profiles for emergency use |
| Diamond Cutting Disc Destructive Cutting | Fully rust locked & broken bolt seizure | 5 mins fast removal per bolt | Partial damage on bracket hole position | Offshore floating PV emergency rush repair & mass broken bolt replacement |
1. Pre-treatment penetration: Inject dedicated metal penetrating rust remover into thread gaps and stand for 10 mins to dissolve internal salt scale & rust; 2. Non-destructive disassembly priority: Use extended torque wrench with slow force increase, pneumatic impact wrenches are forbidden to avoid direct bolt fracture; 3. Rust cleaning procedure: Clean thread and bracket contact rust with steel wire brush, wash away salt with clean water and fully air dry; 4. Anti-corrosion reassembly matching: Replace brand new thickened EPDM insulating gaskets, evenly coat long-term outdoor anti-corrosion grease on threads, spray zinc-rich primer to seal contact surfaces; 5. Retightening torque rule: Fasten bolts per PV standard torque and reserve allowance for thermal deformation to prevent re-seizure caused by temperature difference.
1. Inland PV stations: 1 inspection per autumn, clean surface flash rust and retighten loose bolts, replace aging gaskets every 3 years; 2. Riverside & lakeside PV: Two inspections every spring & autumn, re-coat anti-corrosion grease on exposed threads; 3. Coastal & tidal flat PV: Inspection every 6 months, focus on tracker moving threads, disassemble and maintain in advance when slight seizure appears; 4. Offshore floating PV: Randomly inspect 20% bracket fasteners per year, fully replace aged rusted accessories to eliminate mid-operation fracture safety hazards.