Duct optical cable is an outdoor optical cable used in access networks or user premises networks.
A type of communication optical cable laying method.
What are the steps required for pipeline laying of optical fiber cables? Pipe laying is generally in urban areas, and the environment for pipe laying is relatively good, so there are no special requirements for the sheath of optical cables and no armor is required.
Before laying the pipeline, the length of the laying section and the location of the connection point must be selected.
Mechanical bypass or manual traction can be used during laying.
The pulling force at one time should not exceed the allowable tension of the optical cable.
The materials for making pipes can be selected from concrete, asbestos cement, steel pipes, plastic pipes, etc. according to geography.
1. Clean and test the pipeline. Before laying the optical cable, the pipeline should be cleaned and tested section by section.
Use a special cleaning tool when cleaning. After cleaning, use a test rod for test pass inspection.
The inner diameter of the plastic sub-tube inside the pipe should be 1.5 times the outer diameter of the optical cable.
When more than two sub-pipes are placed in a cement pipe hole, the equivalent total outer diameter of the sub-pipes should be less than 85% of the inner diameter of the pipe hole.
2. Lay out plastic sub-pipes. When placing two or more plastic sub-pipes, if the pipes are of different colors, the ends do not need to be marked; if the pipes are of the same color or have no color, the ends should be marked. Mark the heads individually.
The length of the plastic sub-pipe should not exceed 300m, and it is required that the plastic sub-pipe must not have joints in the middle of the pipe.
In addition, when laying out plastic sub-pipes, the ambient temperature should be between 50 and +50°C to ensure that their quality is not affected.
The plastic sub-pipes that have been laid out should be fixed with the cement pipes in time to prevent the sub-pipes from sliding.
In addition, the sub-tube opening must be temporarily blocked to prevent foreign matter from entering the tube.
Plastic sub-pipes should be left with sufficient length in the manhole or hand hole according to the design requirements.
3. Optical cable traction The length of a single traction optical cable should generally be less than 1000m.
When this distance is exceeded, segmented traction or auxiliary traction should be added in the middle to reduce cable tension and improve construction efficiency.
In order to protect the outside of the optical cable from damage during the pulling process, when the optical cable penetrates into pipe holes, pipe corners or crosses other obstacles.
Protective measures such as guide devices or bell mouth protective tubes should be used.
In addition, neutral lubricant and other materials can be applied to the outside of the optical cable as needed to reduce the frictional resistance when the optical cable is pulled.
4. After laying the optical cable with a reserved margin, the optical cables should be placed on the specified pallet one by one in the manhole or hand hole, and an appropriate margin should be left to prevent the optical cable from being too tight. .
When optical cables in manholes or hand holes need to be connected, the reserved length should comply with the minimum values specified in the table below.
Table stipulated reserved lengths for optical cable laying 5. Joint treatment There should be no joints in the pipe hole in the middle of the pipe for optical cables.
When the optical cable does not have a joint in the manhole, the optical cable is required to be bent and placed on the optical cable pallet for fixation and binding. It must not pass directly in the middle of the manhole. Otherwise, it will affect construction and maintenance and easily cause damage to the optical cable.
When the optical cable has connectors, it should be protected by materials such as snake-shaped hoses or soft plastic tubes, and placed on pallets to be fixed and tied.
6. Blocking and marking The outlet end of the pipe hole where the optical cable is inserted should be tightly blocked to prevent water or debris from entering the pipe.
Optical cables and their connections should have identification marks, and indicate the number, cable model and specifications, etc.
