Construction of Non-Metallic Duct Loose Tube Optical Fiber Cable

Application

Non-metallic duct fiber optic cables are installed for general application purpose for long haul distances. These types of cables are suitable to install near to electrical cables. Since there are no metallic elements used in the cable design, non-metallic type duct fiber cables are safe from the adverse effects of electrical flux.

Cables are installed in ducts usually made of HDPE. The simple design and construction of non-metallic duct cables make them the cheapest of the available types of optical fiber cables. Non-metallic duct fiber optic cables are generally installed in areas that are free from rodent and termite attacks.

These cables can be installed in conduits that run inside the campuses for a few kilometers. The cables installed in the duct are safe from outside environmental effects. Duct fiber optic cables will comply with IEC-60794-3-10 March 2002

Design

Construction and design of duct non metallic fiber optic cable PE sheath fiber optic mania social network

Construction

This is a loose tube, nonmetallic duct cable. A certain number of optical fibers are placed inside the plastic tubes. Optical fibers will have different colors for identification within a tube. A tube typically contains twelve colored optical fibers. The colors are; Blue, Orange, Green, Brown, Grey, White, Red, Black, Yellow, Violet, Pink, Aqua. Tubes are also colored to identify from other tubes. Tube colors may have the same color sequence as the colored optical fibers. Tube colors can also be customized. Tubes are filled with thixotropic jelly to prevent the entry of moisture. Jelly provides a cushion for the fibers and also helps to hold them with an excess length inside the tube.

Tubes are stranded over a central strength member, typically Glass fiber reinforced plastic (GFRP). GFRP is an anti-buckling element and provides the required tensile strength to the cable. The tubes stranded over GFRP form the core unit, which may be filled with gel to achieve water blocking performance. Alternatively, water swellable yarns may also be applied in the interstice space to achieve water blocking performance. The core unit is then wrapped with a tape, either polyester tape or water swellable tape.

An outer layer of polyethylene provides safety to the cable elements from environmental as well as mechanical stresses during installation and operational lifetime of the cable. Ripcords are provided to help to rip the sheath for termination and jointing of optical fibers.

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