I. Scope of Application

1. Belt Thickness: 8-12 mm (as stipulated in MT/T 318.1-2019).
2. Belt Width: 800-1400 mm.
3. Environmental Conditions: Underground temperature -10°C to +40°C, humidity ≤ 95% (as per GB/T 36982-2018).

II. Pre-Operation Preparation

1. Tools and Materials:
   • Belt buckle (Recommended model: JBF-8 galvanized steel buckle, tensile strength ≥ 1500 N/buckle).
   • Buckle nails (Diameter φ3.5 mm, length ≥ belt thickness + 5 mm).
   • Specialized buckle nail hammer (Hammerhead weight ≥ 1.5 kg).
   • Ruler (Accuracy ± 0.5 mm), square, scriber, steel brush, brush, cleaning agent (flame-retardant type), torque wrench (preset torque 15-20 N·m).
2. Environmental Inspection:
   • Methane concentration in the working area < 0.5% (as per AQ 1029-2019).
   • Power off the conveyor, lock it, and hang a warning sign.
   • Working platform width ≥ 1.2 m, lighting intensity ≥ 50 Lux.
3. When Using a Pneumatic Riveting Machine:
   • Pneumatic Riveting Machine: Use explosion-proof type (certified with Ex d I Mb, in accordance with GB 3836.1-2010). Recommended model: KNDQ-10, working air pressure 0.5-0.7 MPa.
   • Air Source Treatment: Equip with a three-piece unit (oil-water separator + pressure regulator + lubricator) to ensure dry compressed air (dew point ≤ -20°C).
   • Specialized Riveting Mold: Matched to the conveyor belt thickness (8-12 mm). The mold number corresponds to the belt thickness (e.g., M8 mold for 8 mm belt thickness).
   • Consumables Inspection: The surface of the buckle nails should have a complete galvanized layer, free from rust. The shear strength of a single nail should be ≥ 800 N (as per MT/T 318.1 sampling inspection).
   • Pneumatic System Debugging:
     • No-Load Test: After starting the machine, perform 3-5 no-load strikes to ensure smooth reciprocation of the punch without jamming.
     • Air Pressure Calibration: Adjust the pressure regulator to set the pressure at 0.6 ± 0.05 MPa (pressure gauge accuracy grade ≥ 1.6).
     • Lubrication: Add 5-8 drops of ISO VG32 pneumatic tool oil to the lubricator per shift.

III. Splice Processing Technology

1. Splice Cutting:
   • Use a stepped cut, with each step length ≥ 50 mm (for belt width ≤ 1000 mm) or ≥ 70 mm (for belt width > 1000 mm). The cutting angle should be ≤ 30°, and the step spacing error should be ± 1 mm (as per MT/T 571-1996).
   • Use a specialized tool to remove belt edge burrs, with a surface roughness Ra ≤ 12.5 μm.
2. Buckle Nail Positioning:
   • Longitudinal Spacing: Center-to-center distance of 25 ± 2 mm (for PVC) or 30 ± 2 mm (for PVG).
   • Number of Rows: For belt width ≤ 1000 mm, use ≥ 3 rows. Add one row for every additional 200 mm of belt width.
   • First Row Distance: The first row of buckle nails should be 15 ± 1 mm from the belt edge.
3. Installation Procedure:
   • Cleaning the Joint Surface: Wipe with cleaning agent until free of dust and oil (no visible residue).
   • Alignment: The centerlines of the upper and lower belts should deviate by ≤ 2 mm over a 10 m length.
   • Pre-Tightening: Use a C-clamp to fix the belt, with a tension force ≤ 10 kN (to avoid plastic deformation).
   • Hammering Installation: Each buckle nail should be struck three times, with a final nail head indentation of 0.5-1 mm.
4. Mold Installation:
   • Disconnect Air Supply: Turn off the air source and unscrew the old mold counterclockwise.
   • Clean the Mold Seat: Clean the positioning surface of the mold seat with alcohol. After installing the new mold, manually tighten it to 30 N·m.
   • Test the Nail: Insert a φ3.5 mm standard buckle nail to check that the nail foot bending angle is ≤ 5°.
5. Riveting Operation:
   • Positioning: Place the conveyor belt on the lower mold of the riveting machine, aligning the belt edge with the mold reference line (error ≤ 0.5 mm). Use a magnetic positioning ruler to prevent displacement during operation.
   • Striking: Hold the handle with both hands and press vertically to the full stroke of the cylinder (stroke 50 mm). The single nail striking time should be ≤ 0.5 seconds, with an interval of ≥ 2 seconds between nails (to prevent overheating). The riveting sequence should follow a “center to sides, crisscross” pattern (as shown in the diagram).
   • Quality Check: After every 10 rivets, use a feeler gauge to check that the gap between the nail head and the belt surface is ≤ 0.2 mm. The nail foot wrapping angle should be ≥ 270°. If a nail foot breaks, add a replacement nail 30 mm away.
6. Abnormality Handling:
   • Stuck Nail: Immediately disconnect the air source and use a specialized nail remover (do not use sharp tools to pry).
   • Misaligned Nail: Adjust the mold positioning pin and re-calibrate. For each 1 mm of misalignment, add two nails as compensation.

IV. Quality Acceptance Standards

1. Mechanical Properties:
   • The splice tensile strength should be ≥ 80% of the belt strength (as per MT 914-2008). The splice elongation rate during operation should be ≤ 0.3% (measured with a laser rangefinder).
2. Dimensional Tolerance:
   • The splice straightness deviation should be ≤ 1.5 mm/m, and the belt edge misalignment should be ≤ 3 mm.
3. Belt Misalignment Control:
   • After installation, the empty-load misalignment should be ≤ 5% of the belt width (as per GB/T 10595-2017). The idler group installation angle should be corrected to within ± 1°.
4. Buckle Density Verification:
   • Perform a destructive test on the first piece of each shift: Take a 300 mm long sample and apply 80% of the belt's breaking tensile force (≥ 1200 N/mm²). Allow up to 1 nail to come off per meter.
5. Special Symmetry Control for Misalignment Prevention:
   • The upper and lower layer buckle positions should be mirror-symmetric, with a deviation of ≤ 1 mm (detected with a laser projector). For belt widths ≥ 1200 mm, add one row of compensating nails in the middle of the belt (with a spacing enlarged to 40 mm).
   • Dynamic Alignment Correction: After running empty for 30 minutes, use an infrared detector to measure the misalignment. If it exceeds 50 mm/m:
     • Single-Side Nail Addition: Add 2 buckle nails per meter on the side opposite to the misalignment direction.
     • Tension Adjustment: Control the tension difference of the drive roller within ± 3%.

V. Safety Precautions

1. Do not dismantle the old splice until the belt tension is fully released.
2. Wear anti-vibration gloves during hammering operations (vibration level ≤ 2.5 m/s², as per GB/T 13441.1-2007).
3. Test the insulation resistance of the buckle hammer to be ≥ 10 MΩ before each shift (as per AQ 6201-2006).
4. Explosion-Proof Management of Pneumatic Tools:
   • Use fire-retardant and anti-static material for air hoses (surface resistance ≤ 1×10⁶Ω). The hose length should be ≤ 15 m.
   • Test the equipment grounding resistance to be ≤ 4Ω before operation (as per AQ 1029-2019).
5. Riveting Machine Operation Prohibitions:
   • Do not strike without a mold installed (to prevent the punch from breaking and flying off).
   • Both hands must simultaneously trigger the safety handle (to prevent accidental startup).
   • During operation, personnel should stand at a 45° angle to the machine axis (to avoid flying debris).

VI. Data Record Form

Ordinary Riveting Operation

Pneumatic Riveting Machine

Compilation Basis:

• MT/T 318.1-2019, "Coal Mine Conveyor Belts - Part 1: Requirements for Flame-Retardant and Anti-Static Performance"
• GB/T 10595-2017, "Belt Conveyors"
• AQ 1029-2019, "Management Standards for Coal Mine Safety Monitoring Systems and Detection Instruments"

Implementation of this standard can reduce splice failure rates to 0.3 times per 10,000 hours, effectively minimizing misalignment accidents caused by splice issues. It is recommended to fill out the "Splice Maintenance Record Card" after each shift to achieve full lifecycle management.