Something About armored cable

- Dec 01, 2020-

What is armored optical cable?

Armored optical cable, as the name suggests, is an optical cable wrapped with a protective "armor". Its armor is mainly used to protect the optical fiber cable from animal bites, moisture erosion or other damage.

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Why use armored optical cable?

In the past, outdoor optical cables were usually laid in strong ducts to prevent the cables from being damaged by external forces. However, this optical cable laying method is very complicated, and it will take a lot of time and labor costs. Therefore, someone designed to add a layer of metal armor to protect the core of the fiber optic cable, which is also known as armored fiber optic cable. The armored optical cable has the function of resisting strong pressure and stretching, can effectively adapt to the harsh outdoor environment, and the wiring is much more flexible than pipeline wiring. Now, armored optical cables have been widely used in the field of optical communications.

Structure of armored optical cable

1. Outer sheath: In the design of armored optical cable, the outer sleeve can protect the optical cable from solvents and abrasion. Normally, the outer sleeve is made of plastic, such as polyethylene.

2. Metal armor: between the outer sleeve and the inner sheath is armor. The armor material is difficult to cut, bite and burn, and it can also prevent the cable from being stretched during the laying process. As shown in the figure below, the 12-core armored optical cable has 12 optical fibers and two inner and outer sheaths. The metal armor is located between the inner and outer sheaths, and there is a layer of aramid yarn between the outer sheath and the metal armor. :

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3. Inner sheath: It is a protective and flame retardant material that can support the internal optical cable harness. In simple terms, in an armored optical cable, the buffer duct is surrounded by a layer of aramid yarn, a layer of polyethylene sheath, and a layer of corrugated steel armor.

Armour type

Armored fiber optic cables can be divided into indoor armored fiber optic cables and outdoor armored fiber optic cables according to the application of the fiber optic cable. In addition, armored optical cables can also be divided into interlocking armored cables and corrugated armored cables according to different types of metal armors.

Indoor armored optical cable: Indoor armored optical cable includes single-layer armored and double-layer armored optical cables. Among them, double-layer armored optical cables are used in shallow seas near shore, and single-layer armored optical cables are used for other occasions outside of these extreme conditions.

Outdoor armored fiber optic cable: Outdoor armored fiber optic cable can be divided into light armored fiber optic cable and heavy armored fiber optic cable. Under normal circumstances, heavy-duty armored optical cables are used in river bottoms and seabeds, so the price of light-duty armored optical cables is cheaper than heavy-duty armored optical cables.

Interlocking armored optical cable: Interlocking armor is a twisted optical cable with aluminum armor, which is often used in indoor and outdoor general environments, with high durability and high compression resistance.

Corrugated armored fiber optic cable: Corrugated armored fiber optic cable is made of longitudinal folds wrapped with steel tape. It is often used in outdoor environments. It has super mechanical properties and provides protection against rodents.

Application of armored optical cable

According to different laying environments, armored optical cables can be divided into tight sleeve armored optical cables and loose sleeve armored optical cables. Loose sheathed armored cables are usually used in outdoor applications; tight sheathed armored cables can be used in indoor applications and indoor/outdoor applications.

The figure below is a structural diagram of indoor armored optical cable. The metal armor is interlocking armor, and the sheath can be a riser type or a low-smoke halogen-free type:

Indoor/outdoor armored optical cables are widely used in modern telecommunications networks. They are the link connecting two or more building networks. The following figure shows the internal structure of common multi-core indoor/outdoor armored optical cables:

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Concluding remarks

In the field of modern optical fiber communication, any optical fiber failure may cause significant financial and material losses. Therefore, protecting the optical fiber is the top priority in the installation of optical fiber communication systems. The armored optical cable wrapped with a protective "armor" on the outside of the optical fiber satisfies the requirements of people's anti-rat bite, moisture-proof, and tensile resistance.