Basic knowledge of optical cables

The basic knowledge of optical cables is introduced through laying, types, construction, precautions, and fiber optics. The specific content is as follows:

1、 Laying

1. General provisions

The bending radius of the optical cable should not be less than 15 times the outer diameter of the cable, and should not be less than 20 times during construction.

The traction force for laying optical cables should not exceed 80% of the allowable tension of the cable. The instantaneous traction force shall not exceed 100% of the allowable tension of the optical cable. The main traction should be added to the reinforcement component (core) of the optical cable.

1.3 The fiber optic cable traction end can be prefabricated or fabricated on site. Directly buried or underwater armored optical cables can be used as mesh covers or traction terminals.

To prevent twisting and damaging the optical cable during traction, a swivel should be added between the traction end and the traction cable.

When laying the optical cable, it should be released from above the cable reel and kept in a relaxed arc shape. During the process of laying optical cables, there should be no twisting, and it is strictly prohibited to have small circles or surges.

When mechanical traction is used for fiber optic cable laying, centralized traction, intermediate auxiliary traction, or dispersed traction should be selected based on factors such as traction length, terrain conditions, and traction tension.

1.7 The traction machine used for mechanical traction shall meet the following requirements:

1) The traction speed adjustment range should be 0-20 meters per minute, and the adjustment method should be stepless speed regulation;

2) The traction tension can be adjusted and has automatic stopping performance, which means that when the traction force exceeds the specified value, an alarm can be automatically issued and the traction can be stopped.

1.8 Lay optical cables, organize them tightly, and assign a dedicated person to command. There should be good communication methods during the traction process. Untrained personnel are prohibited from taking up their posts and working without contact tools.

After the fiber optic cable is laid out, it should be checked whether the fiber is in good condition. The end of the optical cable should be sealed and not immersed in water.

2. Pipeline optical cable

2.1 Before laying pipeline optical cables, the following preparations should be made

1) Check the position of the pipe holes occupied by the optical cable according to the design;

2) The hole positions selected on the same route should not be changed. When changing or turning, the requirements for the bending radius of the optical cable should be met;

3) Clean the pipe holes used.

2.2 When manually laying optical cables, each entry hole should be manned; When mechanically laying optical cables, there should be someone on duty to turn and enter the hole.

2.3 When the optical cable passes through the pipe hole or when the pipeline bends or intersects, a guiding device or horn mouth protective tube should be used, and the outer protective layer of the optical cable should not be damaged. Neutral lubricant can be applied around the optical cable as needed.

2.4 The length of a single optical cable traction is generally not more than 1000 meters. Eight character segmented traction or intermediate auxiliary traction should be adopted.

After the installation of the 2.5 optical cable, a dedicated person should give unified command and place the cables one by one on the designated pallets, leaving appropriate allowance to avoid the cables being too tight.

The reserved length of the optical cable at the entrance hole where the joint is located should comply with the specifications in the table; The design requires the reserved optical cable to be tightened too tightly.

2.7 The protection measures for pipeline optical cables should meet the following requirements:

1) The optical cable entering the hole can be protected by a serpentine hose (or soft plastic tube) and tied to the cable tray or treated according to the design requirements;

2) The pipe mouth should be blocked;

3) The optical cable entering the hole should have identification marks;

4) Antifreezing measures should be taken according to design requirements in cold regions to prevent damage to optical cables.

The laying method of plastic sub pipes is basically the same as that of optical cable laying, and should also meet the following requirements:

1) When laying two or more colorless labeled sub tubes, markings should be made at the ends;

2) The ambient temperature for laying plastic sub pipes should be between -5 ℃ and+35 ℃;

3) The length of continuous plastic sub pipes should not exceed 300 meters;

4) The tensile force of the traction tube should not exceed the tensile strength of the pipe material, and the traction speed should be uniform;

5) The remaining length of the sub tube in the inlet hole should meet the design requirements;

6) Plastic pipe plugs (other methods can also be used) should be installed in the pipe holes where plastic sub pipes are inserted to secure the sub pipes;

7) There shall be no joints in the middle of the pipeline for the sub pipe;

8) After the sub pipe is laid out, the pipe mouth should be temporarily blocked; The sub pipes that are not used in this project are installed with plugs (caps) at the pipe ends.