1. Clean and test
Before laying optical cables, the pipe holes shall be cleaned section by section and tested. During cleaning, the autocratic cleaning tool shall be used, and the test rod shall be used for test pass inspection after cleaning. The inner diameter of the plastic sub pipe shall be 1.5 times of the outer diameter of the optical cable. When more than two sub pipes are laid in one cement pipe hole, the equivalent total outer diameter of the sub pipe shall be less than 85% of the inner diameter of the pipe hole.
2. Lay plastic sub pipes
When more than two plastic sub pipes are put through, if the pipes are of different colors, the ends may not be marked. If the pipes have the same color or no color, their ends shall be marked respectively. The laying length of plastic sub pipes shall not exceed 300m, and it is required that plastic sub pipes shall not have joints in the middle of the pipes. In addition, during the laying operation of plastic sub pipes, the ambient temperature should be between – 5 ° C and + 35 ° C to ensure that its quality will not be affected. The plastic sub pipes laid shall be fixed together with the cement pipe in time to prevent the sub pipes from sliding. In addition, the sub pipe orifice shall be temporarily blocked to prevent foreign matters from entering the pipe. The plastic sub pipe shall have sufficient length in the inlet hole according to the design requirements.
3. Optical cable traction
The primary traction length of optical cable shall generally be less than 1000m. When the distance is exceeded, sectional traction or auxiliary traction shall be adopted at the middle position to reduce the tension of optical cable and improve construction efficiency. In order to protect the outside of the optical cable from damage during traction, when the optical cable penetrates into the pipe hole, turns of the pipe or crosses with other obstacles, protective measures such as guiding device or bell mouth protective tube shall be adopted. In addition, neutral lubricant and other materials can be applied on the outside of the optical cable as needed to reduce the friction resistance during optical cable traction.
4. Reserved margin
After the optical cable is laid, the optical cable shall be placed on the specified support plate one by one in the access hole or hand hole, and appropriate allowance shall be reserved to prevent the optical cable from being too tight. When the optical cable in the access hole or handhole needs to be connected, the reserved length shall meet the minimum value of relevant regulations.
5. Joint treatment
The optical cable shall not have joints in the pipe hole in the middle of the pipe. When the optical cable has no joint in the manhole, it is required to bend the optical cable and place it on the optical cable support plate for fixation and binding. It is not allowed to pass directly through the middle of the manhole, otherwise it will not only affect the construction and maintenance, but also easily lead to the damage of the optical cable. When the optical cable has a joint, it shall be protected by pipes such as snake shaped hose or soft plastic pipe, which shall be fixed and bound on the support plate.
6. Plugging and marking
The outlet end of the pipe hole through which the optical cable passes shall be sealed tightly to prevent water or sundries from entering the pipe. The optical cable and its connection shall be provided with identification marks, and the number, optical cable model and specification shall be indicated. Antifreeze measures shall also be taken in severe cold areas to prevent optical cables from being damaged by freezing. If the optical cable may be damaged by collision, insulating plates can be set on or around it for partition protection.