Before restarting a production line after a long shutdown, the core principles are safety first, inspection second, and trial run third. Verify each item step by step to avoid equipment damage or safety incidents caused by starting up with hidden dangers. The following is a practical checklist for pre-restart preparation:

I. Safety Preparation (Priority Implementation to Eliminate Risks)

1. Lockout/Tagout (LOTO)

   Strictly implement lockout/tagout procedures: cut off main power, air supply, and water supply, hang "Under Maintenance/Do Not Start" warning signs to prevent misoperation.

2. Personnel and Environment Confirmation

   Clear away debris, oil stains, and water around the equipment to ensure unobstructed passages; confirm all personnel have evacuated the hazardous areas of the equipment, and clarify the division of labor for startup command and operation.

3. Safety Device Inspection

   Check that emergency stop buttons, safety doors, light curtains, guardrails, limit switches, etc., are intact, properly reset, and free from damage or obstruction.

II. Basic Equipment Inspection (Item-by-Item Check from Power to Core Components)

1. Power System Inspection

• Electrical: Check power distribution cabinets, junction boxes, and motor terminals for looseness, oxidation, or water ingress; confirm normal voltage and current, and no fault alarms on frequency converters or PLCs.

• Pneumatic/Hydraulic: Inspect air and oil pipes for leaks or aging, ensure pressure values are within the standard range; drain accumulated water from filters, and verify that hydraulic oil level and temperature meet standards.

2. Transmission and Moving Parts

   Check the tension of belts and chains, and inspect gears, bearings, and guide rails for abnormal noise or jamming; manually rotate the equipment (with power off) to confirm smooth rotation without sticking.

3. Lubrication and Cooling Systems

   Refill lubricating oil/grease according to the lubrication schedule, and confirm normal oil level and quality; check that cooling water and oil circuits are unobstructed, free from blockages or leaks, and that coolant/oil temperature meets standards.

4. Key Components and Wear Parts

   Inspect tools, molds, rollers, conveyor belts, nozzles, etc., for wear, deformation, or cracks; replace aged or expired wear parts, and tighten loose bolts and nuts.

III. Process and Material Preparation (Match Production Needs to Avoid Process Deviations)

1. Process Parameter Review

   Compare with process documents to confirm correct settings of temperature, pressure, speed, time, formulas, and other parameters with no omissions or incorrect modifications; restore default process parameters first after a long shutdown.

2. Material and Consumable Preparation

   Clean residual materials in silos and hoppers (to prevent caking or deterioration), and replace with new batches of qualified raw materials; prepare packaging materials, auxiliary materials, and consumables, and confirm that material specifications are matched.

3. Tooling and Fixture Reset

   Check that tooling, fixtures, and positioning jigs are intact with accurate positions and normal clamping force; clean impurities on the surface of tooling to ensure accurate product positioning.

IV. Auxiliary System Inspection (Ensure Production Continuity)

1. Utility Confirmation

   Check that utilities such as compressed air, cooling water, steam, and nitrogen are supplied stably, with pressure, flow rate, and purity meeting requirements.

2. Inspection and Control Systems

   Calibrate sensors, instruments, flow meters, weighing devices, etc., to ensure accurate data; test the normal operation of automatic inspection, alarm, and rejection functions without failure.

3. Cleaning and Sanitation (Key for Food/Pharmaceutical Industries)

   Clean the inner walls of equipment, pipelines, and product-contacting parts in accordance with hygiene standards, complete disinfection and sterilization; confirm no residual cleaning agents or foreign matters, and compliance with production hygiene requirements.

V. Trial Run and Verification (Start Gradually and Verify Step by Step)

1. No-Load Trial Run

   Release safety locks, first start with inching, then run at low speed without load for 5-10 minutes, observe equipment operation, abnormal noise, vibration, and temperature to confirm no abnormalities.

2. Load Trial Production

   Put in a small amount of materials, conduct trial production according to normal processes, and check whether product size, appearance, and performance are qualified; track equipment operation status and adjust parameters in a timely manner.

3. Problem Closure

   Immediately shut down the equipment to handle abnormal noise, leaks, product defects, and other problems found during the trial run; formal mass production is prohibited until the problems are resolved.

VI. Recording and Confirmation (Keep Records for Traceability and Clear Responsibility)

1. Fill in the Equipment Restart Checklist, record inspection results, parameters, and trial run conditions item by item, and confirm with signatures from operators and equipment principals.

2. Organize maintenance records and spare parts replacement records during the shutdown, and file them together with restart records for subsequent traceability.