What is the difference between the duct optical cable and the direct buried optical cable? The duct optical cable is an outdoor optical cable used in the access network or the user premise network. A method of laying communication optical cables. Pipe laying is generally in urban areas, and the environment for pipe laying is relatively good, so there is no special requirement for the sheath of the optical cable, and no armor is required. Before the pipeline is laid, the length of the laying section and the location of the connection point must be selected.

When laying, mechanical or manual traction can be used. The traction force of a traction should not exceed the allowable tension of the optical cable. The material for making the pipeline can be selected from concrete, asbestos cement, steel pipe, plastic pipe, etc. according to the geography.

Direct Buried Optical Cable

Direct buried optical cable is a way of laying communication optical cables. This kind of optical cable is armored with steel tape or steel wire on the outside, and is directly buried in the ground. It is required to have the performance of resisting external mechanical damage and preventing soil corrosion.

What is the difference between duct optical cable and direct buried optical cable

The following preparations should be made before laying the pipeline optical cable

1) Check the position of the tube hole occupied by the optical cable according to the design;

2) The hole position selected on the same route should not be changed. If it is changed or turned, it should meet the requirements of the bending radius of the optical cable;

When the optical cable is laid manually, each manhole should be guarded; when the optical cable is mechanically laid, the turning manhole should be guarded.

When the optical cable passes into the pipe hole or the pipe turns or crosses, a guide device or a bell mouth protection tube should be used to prevent the outer sheath of the optical cable from being damaged. A neutral lubricant can be applied around the cable as needed.

The pulling length of the optical cable at one time is generally not more than 1000 meters. When it is too long, 8-character segmental traction or auxiliary traction in the middle should be adopted.

After the optical cable is laid, it should be commanded by a special person, and the optical cable should be placed on the specified pallet one by one, and an appropriate margin should be left to prevent the optical cable from being too tight.

The reserved length of the optical cable in the manhole where the connector is located should meet the requirements in the table; the design requires that the optical cable specially reserved is too tight.

The protective measures for duct optical cables shall meet the following requirements:

1) The optical cable in the manhole 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 mouth of the pipe should be blocked;

3) The optical cable in the manhole should have an identification mark;

4) Antifreeze measures should be taken according to design requirements in severe cold areas to prevent damage to optical cables.

The laying method of the plastic sub-pipe is basically the same as that of the optical cable, and the following requirements should also be met:

1) When laying more than two sub-pipes without color marks, marks should be made at the ends;

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

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

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

5) The excess length of the sub-pipe in the manhole should meet the design requirements;

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

7) The sub-pipe shall not have joints in the middle of the pipe;

8) After the sub-pipes are laid out, the nozzles should be temporarily blocked; the sub-pipes not used in this project must be plugged (caps) at the pipe ends.

Direct Buried Optical Cable

The distance between the directly buried optical cable and other buildings and underground pipelines should meet the specified requirements.

Optical cables laid in the same ditch must not cross or overlap, and should be pulled separately and laid at the same time.

The laying of direct buried optical cables shall meet the following requirements:

1) The depth of the cable ditch should meet the requirements, and the bottom of the ditch should be flat and free of gravel; the bottom of the rocky and semi-rocky ditch should be paved with 10 cm thick fine soil or sand;

2) For mechanical traction, ground pulleys should be used;

3) When manually lifting, the optical cable should not bend less than the specified radius of curvature, drag the floor, and pull too tightly;

4) The optical cable must be placed flat on the bottom of the ditch, and must not be vacated or arched;

5. When the optical cable is laid on a slope with a slope greater than 20° and a slope length greater than 30 meters, it should be laid in an "S" shape or handled according to the design requirements;

6) During or after deployment, the sheath of the optical cable should be checked in time, and any damage should be repaired immediately; after the laying of the direct buried optical cable, the insulation resistance of the cable sheath to the ground should be checked.

7) The optical fiber and copper wire in the optical cable must be inspected and confirmed to meet the quality acceptance standards before the entire ditch can be returned to the soil.

The backfill soil of optical cable trench shall meet the following requirements:

1) Backfill 15 cm thick broken soil or fine soil first, it is strictly forbidden to push stones, bricks, frozen soil, etc. into the ditch, and it should be leveled manually;

2)The backfill should be 10 cm above the ground.