Key Points for Air-blown Optical Cable Laying

Air-blown optical cables are installed by combining mechanical pushing with high-speed airflow to efficiently propel the cable through pre-installed ducts. 1.

Planning and Preparation

Begin by carefully planning the cable route, considering existing infrastructure, obstacles, and access points. Clear the pathway of debris, sharp edges, or moisture that could damage the cable. Gather all necessary equipment, including the blowing machine, compressed air source, fiber optic cables, connectors, and lubricants if needed.

2.

Cable Pathway Preparation

Inspect and clean the duct or microduct to ensure smooth airflow. Remove dust, moisture, or obstructions that could increase friction or cause cable damage. Ensure the conduit diameter is slightly larger than the cable to facilitate easier blowing and reduce required air pressure.

3.

Cable Preparation

Prepare the fiber optic cable by stripping the outer sheath and buffer tubes as required, exposing the fibers for connection. Select the appropriate cable type (single-mode, multi-mode, armored, or unarmored) based on the network requirements. Check the cable flexibility and stiffness, as stiffer cables perform better in straight ducts, while flexible cables handle multiple bends more effectively.

4. Crash Test (Optional but Recommended)Perform a crash test to determine the maximum pushing force. Push the cable into a short, sealed duct section to ensure the cable does not buckle or the jacket does not get damaged.

Gradually increase the pushing force until the maximum safe limit is identified. 5.

Cable Blowing

Attach the cable to the blowing head, which has seals to grip the cable. Connect the air source (compressor or nitrogen cylinder) to the duct inlet. Begin by mechanically pushing the cable a few hundred meters using the tractor mechanism or rollers.

Then, gradually introduce compressed air to create a high-speed airflow that propels the cable through the duct. Maintain minimal air pressure to avoid damaging the cable. 6.

Cable Installation and Route Control

Monitor the cable as it moves through the duct, ensuring it remains in a floating condition to reduce friction. Adjust air pressure and pushing force as needed, especially around bends or undulations. Use lubricants if necessary to further reduce friction.

7.

Post-

Installation Checks

After the cable is fully installed, inspect it for any damage, kinks, or excessive tension. Verify that the cable length and routing match the planned design. Ensure connectors and terminations are properly installed and tested for signal integrity.

Key Considerations

Avoid excessive air pressure to prevent cable damage. Temperature affects cable flexibility; avoid installing in extremely cold conditions. Use low-friction cables and lubricants to improve blowing efficiency.

Stiffer cables are preferable for long, straight ducts; flexible cables are better for complex routes. Following these steps ensures a safe, efficient, and reliable installation of air-blown optical cables.