Common models and types of outdoor optical cables

Outdoor optical cable, simply speaking, an optical cable used outdoors, is a kind of optical cable. It is called an outdoor optical cable because it is most suitable for outdoor use. It is durable and can withstand wind, sun, cold and freezing, and the outer packaging is thick. It has some mechanical and environmental characteristics such as pressure resistance, corrosion resistance and tensile strength.

What types of outdoor optical cables are there?

Commonly used outdoor optical cables are divided into two structures: central bundle tube type and layer stranded optical cable:

① Central tube optical cable: The center of the optical cable is a loose tube, and the strengthening member is located around the loose tube. Such as the common GYXTW type optical cable, the number of cores of the optical cable is small, usually less than 12 cores.

GYXTW optical cable:

Bundle tube: The material of the beam tube is PBT, which is hard but flexible and resistant to lateral pressure.

Colored optical fiber: In order to distinguish each core optical fiber in the communication engineering of the optical cable, a layer of colored plastic is extruded on the bare fiber. The outdoor optical cable is to dye each core bare fiber with ink of different colors. The color of the ink is the same as that of the indoor cable, and there are also 12 types. The color spectrum of the industry standard of the Ministry of Information Industry is as follows: blue, orange, green, brown, gray, ( White), red, black, yellow, purple, pink, green. The use of natural colors instead of white is permitted provided that identification is not affected.

Fiber paste: The bundle tube is filled with fiber paste to play a waterproof role. It can also prevent the fiber core from shaking inside, avoiding possible wear and tear. Moisture-proof, waterproof and anti-oxidation.

Corrugated steel strip: the outside of the bundle tube is coated with a coated corrugated steel strip. The main function of the steel strip in the optical cable is to resist lateral pressure, pull, prevent mice from biting, and protect the bundle tube.

Steel wire: We can see two parallel steel wires on the outside of the steel belt. The function of the steel wire is to enhance the tension of the optical cable. The gray steel wire on the surface is phosphating to prevent the steel wire from rusting.

Optical cable sheath: Outdoor optical cables generally use medium-density polyethylene (PE). There are also orders specifying that low-smoke and halogen-free materials (LSZH) should be used as sheaths. Many manufacturers also use recycled materials as optical cable sheaths to reduce costs. The optical cables made of this material have rough skins, contain a lot of impurities, and are prone to cracking and water seepage. The source of recycled materials is to crush some wire and cable skins, plastic bottles, slippers, etc. and return them to the furnace for re-granulation.

Because there are only 12 colors of optical fibers, the national standard (also international standard) central bundle tube optical cable can only have 12 cores at most. There are also some non-standard central beam tube cables with more than 12 cores, but generally no more than 24 cores. The method is to select one of the two optical fibers of the same color and spray a bar with an inkjet printer at a certain distance to distinguish them. Cables with more than 12 cores generally use layer twisting.

② Stranded optical cable GYTS, GYTA: multiple bundle tubes with optical fibers are stranded on the core strength member in a twisted manner. Such optical cables such as GYTS, GYTA, etc., can be obtained by combining loose tubes Fiber optic cables with larger core counts. The color separation of stranded loose tubes usually uses red and green collars to distinguish colors, which is used to distinguish different loose tubes and different optical fibers.

GYTS type optical cable: In the layer twisted optical cable red, this type and GYTA are the most common. Twist several bundle tubes on a thicker phosphating steel wire, fill the gaps of the twisted cable with water-blocking cable paste, and wrap a circle of plastic-coated steel tape on the outside, and then extrude the sheath.

GYTA type optical cable: The structure of this optical cable is the same as that of GYTS, except that the steel tape is replaced by aluminum tape. The lateral pressure resistance index of the aluminum strip is not as high as that of the steel strip, but the anti-rust and moisture-proof performance of the aluminum strip is better than that of the steel strip. In some environments where the pipe is worn, the GYTA type is used, and the service life of the optical cable is longer.

GYFTY-type optical cable: This type of optical cable is to twist several bundle tubes on a non-metallic reinforced core, fill the twisted gap with cable paste or keep a circle of water-blocking tape, and directly squeeze the sheath without adding armor.

There are many evolutions of this model. It is used in some overhead environments. In order to increase the tensile force of the optical cable, some aramid fibers should be added to the stranded cable core and then extruded sheath. If the central reinforcement uses steel wire instead of non-metallic reinforcing core (FRP), the model is GYTY, without F (representing non-metallic).

GYFB type optical cable: This type of optical cable is composed of single or multiple 2.0 subunit nylon (or equivalent performance material) tight-buffered optical fibers plus high modulus aramid and polyurethane (or equivalent material) sheaths. It is a metal-free optical cable specially designed for rapid wiring or repeated retraction in field operations and complex environments. It is light in weight, high in tension and pressure; good in flexibility; easy to bend; Combustion; wide temperature range and other characteristics. It is suitable for rapid wiring or repeated retraction of field communication systems; radar, aviation and ship wiring; oil fields, mines, ports, live TV broadcasting, communication line repairs and other harsh conditions.

FRP reinforced core: This material is generally made of glass fiber, and the strength of the same outer diameter is greater than the tensile force of the steel wire. It is characterized by non-conductivity, and it is safer to use overhead in a minefield environment. When training optical fibers, we know that optical fibers are drawn from high-purity glass and are not afraid of lightning. However, the metal parts in the middle of the optical cable are easily burned by direct lightning strikes when the optical cable is overhead. Seeing the model with F, we should know that it is mainly lightning protection. The cost of strengthening with FRP is slightly higher than that of steel wire.

Type 53 optical cable: We have seen some models such as GYTA53, GYTY53, this type is to add a layer of steel armor and sheath on the outside of GYTA, GYTY optical cable. Applied in those occasions where the environment is relatively harsh. When you see 53, you should know that it is an extra layer of armor and an extra layer of sheath.