What Is The Difference between Duct Optical cable And Direct Buried Optical Cable?

We often tak about the concept of optical cables, but in fact many friends do not know much about the detailed knowledge ofoptical cables, For example, what are duct optical cables and direct buried ontical cables, or what are the diferences betweenduct optical cables and direct buried optical cables? Let's go and find out.

Duct optical cable:

Duct ontical cable is an outdoor optical cable used in access network or user premises network, A type of communication opticalcable laying method. Duct laying is generally in urban areas, and the environment for duct laying is relatively good, so there areno special reguirements for the sheath of optical cables and no armor is reguired, Betore laying the duct, the length ot the layindsection and the location of the connection point must be selected.

Mechanical bypass or manual traction can be used during laying. The puling force at one time should not exceed the allowabletension of the optical cable. The materials for making ducts can be concrete, asbestos cement, steel ducts, plastic ducts, etc.according to geography.

Direct buried optical cable：

Direct buried optical cable is a communication optical cable laying method. This kind of optical cable is armored with steel stripsor steel wires on the outside and is directly buried underground, t is reauired to resist external mechanical damage and preventsoil corrosion.

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

The following preparations should be made before laying duct optical cables1) 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. lf it is changed or turned, the bending radiusrequirements of the optical cable should be met;

When laying optical cables manually, each manhole should be manned; when laying optical cables mechanically, manholes at thecorners should be manned.

When the optical cable penetrates the duct hole or the duct turns or crosses, a quide device or a bell mouth protective tubeshould be used to avoid damaging the outer sheath of the optical cable. Apply neutral lubricant around the fiber optic cable asneeded.

The length of a single pull of an optical cable is generally no more than 1,000 meters. When the length is too long, figure-8segmented traction or auxiliary traction in the middle should be used.

After the optical cable is laid, a dedicated person should be under unified command to place the optical cable on the specifiedpallet 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 comply with the requirements inthe table; the optical cable that requires special reservation in the design is too tight.

Protection measures for duct optical cables should meet the following requirements:

1) Optical cables in manholes can be protected by snake-shaped hoses (or soft plastic tubes) and tied to cable pallets or handledaccording to design requirements:

2)The duct mouth should be blocked:

3)Optical cables in manholes should have identification marks;

4) in severely cold areas, antifreeze measures should be taken according to design requirements to prevent damage to opticalcables.

The laying method of plastic sub-ducts is basically the same as that of optical cables, and should also meet the followingrequirements:

1) When laying out two or more sub-ducts without color markings, marks should be made at the ends;

2) The ambient temperature where plastic sub-ducts are laid should be between -5oC--+350C.

3) The length of continuously laid plastic sub-ducts should not exceed 300 meters;

4) The maximum puling force of the puling sub-duct should not exceed the tensile strength of the duct, and the puling speedmust be uniform:

5) The remaining length of the sub-duct in the manhole should meet the design requirements;

6) A plastic duct plug should be installed in the hole where the plastic sub-duct is placed (other methods can also be used) to fixthe sub-duct:

7) The sub-duct must not have joints in the middle of the duct;

8) After the sub-ducts are laid out, the duct mouths should be temporarily blocked: sub-ducts not used in this phase of theproject must be installed with plugs (caps) on the duct ends.

The distance between directly buried optical cables and other buildings and underground ducts should meet the specifiedrequirements.

Optical cables laid in the same trench must not cross or overlap. They should be puled separately and laid out simultaneously.

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

1) The depth of the optical cable trench should comply with the regulations, and the bottom of the trench should be smooth andfree of gravel; the bottom of the stony or semi-stony trench should be paved with 10 cm of fine soil or sand;

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

3) When manually lifting, the optical cable should not be bent less than the specified radius of curvature, dragged on the floor, orpulled too tightly, etc.:

4) The optical cable must be placed flat at the bottom of the trench and must not be vacated or arched'

5) When laying optical cables on slopes with a slope greater than 20" and a slope length greater than 30 meters, it should be laidin an "S" shape or handled according to design requirements;

6) During or after the laying process, the outer sheath of the optical cable should be checked in time. lf it is damaged, it shouldbe repaired immediately; after the laying of the directly buried optical cable, the insulation resistance of the optical cable sheathto the ground should be checked.

7) The optical fibers and copper conductors in the optical cable must be inspected and confirmed to meet the quality acceptancestandards before they can be fully trenched and returned to the soil.

Optical cable trench backfill soil should meet the following requirements:

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

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

The above is all about what are duct optical cables and direct buried optical cables and what are the differences between ductoptical cables and direct buried optical cables. l believe that after reading this article, you will have a certain understanding of duct optical cables and direct buried optical cables. Hope it will be helpful for you.