Precautions for optical cable laying using air blowing method

Ensure proper cable handling, controlled air pressure, duct integrity, and pre-installation testing to prevent damage during air blowing installation.Cable Handling and PreparationCheck cable specifications: Use cables suitable for air-assisted installation, including uni-tube, multi-tube, armored, or microduct cables, and ensure they meet the manufacturer's design ratings for tensile strength, bending radius, and crush resistance .Avoid excessive bending: Maintain the cable's minimum bending radius to prevent microbending or macrobending losses .Temperature considerations: Avoid installing cables in extremely cold conditions, as the jacket may become brittle, and cold air can condense or freeze, potentially damaging the cable .Low-friction surfaces: Use cables with low friction coefficients or apply approved lubricants to reduce resistance inside the duct .Equipment and Installation SetupBlowing head and seals: Attach a properly sized blowing head (“bullet”) that matches the cable diameter to ensure a tight seal and efficient air flow .Compressor settings: Use the minimum air pressure required to float the cable through the duct. Excessive pressure can damage the cable jacket or cause buckling .Tractor mechanism: Apply mechanical pushing force near the cable inlet using traction rollers, but avoid exceeding the maximum pushing force determined by pre-installation crash tests .Pre-Installation TestingCrash test: Push the cable into a short, sealed duct section to determine the maximum safe pushing force without damaging the cable jacket or causing buckling .Duct integrity check: Ensure ducts are continuous, properly joined, and pressure-tested to prevent air leaks that reduce blowing efficiency .Operational PrecautionsMonitor cable movement: Continuously observe cable progress to detect any signs of buckling, excessive friction, or obstruction .Control air flow: Gradually increase air pressure and maintain consistent flow to keep the cable floating inside the duct .Mid-assist for long runs: For runs exceeding 1000–1500 meters, consider using intermediate blowing devices to maintain cable momentum and prevent damage .Safety and Environmental ConsiderationsPersonnel safety: Ensure operators are trained in handling high-pressure air equipment and cable installation procedures .Avoid sharp bends and obstacles: Inspect the duct route for sharp bends, debris, or obstructions that could damage the cable during blowing .Environmental conditions: Protect the cable from extreme temperatures, moisture, or ice formation during installation . By following these precautions, air blowing installation can achieve long continuous cable runs efficiently while minimizing the risk of cable damage, ensuring reliable network performance, and maintaining safety standards .