Joint Closure

Joint Closure is a plastic fiber optic box used to fuse two or more optical fibers and store them for protection. It is one of the commonly used equipment for user access points. The fiber closure is a method of placing two or more optical fibers which was fused by splice machine one by one in a standardized order, and winding the excess parts in an inverted figure 8 inside the box. The winding radius should not be less than 4cm (to avoid breaking the optical fiber), and it is required to be neatly wound. The splice closure can protect the join part, and is a necessary and very important equipment for the optical fiber fusion part in the construction of optical cable lines. The quality of the optical closure directly affects the quality of the optical cable line and the service life of the optical cable line.

OFC joint enclosure is also known as fiber joint closure, fiber splice closure or fiber splice case. It belongs to the mechanical pressure sealing joint system and is a continuous protection device that provides optical, sealing, and mechanical strength continuity between adjacent optical cables, it is mainly used for direct and branch connections in various structural optical cable laying methods such as overhead, pipeline, and direct burial.

Fiber Optic Closure Types

According to the connection method of optical cables, there are two types: direct connection and divergent connection.

According to the cable laying methods, there are types such as overhead / aerial, pipeline (tunnel), wall mount, pole mount, and direct burial, etc.

wall mount splice enclosure
Wall mount fiber optic joint enclosure

According to the sealing method, it divide into 2types: heat shrink sealing and mechanical sealing. For horizontal closures, mostly is mechanical seal, but for dome, there  are mainly 2types,which can be distinguish by the dome cable ports.

mechanical splice enclosure sealing method
Mechanical seal
heat shrink splice enclosure sealing method
Heat shrink seal

According to the appearance structure, two types: horizontal fiber optic splice closure (inline closure) and dome fiber optic splice closure.

Dome Closure Series

Yingda can provide all types of dome closures, the dome height and diameter can be custom. Max capacity from 6 cores to 576 cores available. The dome can be heat shrink seal or mechanical seal, and the cable ports can be round, oval shape, the cable port quantity can be 2pcs, 3pcs, 4 pcs, 11pcs or more. The feeder cable enter and exit from the bottom. It is widely used in outdoor pole, wall, duct, manhole, underground, aerial, pipeline, etc.

Inline Closure Series

Yingda inline closure are widely used underground, direct buried, or aerial mount, it is outdoor waterproof IP68 protection, all the metal parts used are stainless steel and all closures are made of brand new materials. 

FTTH Closure

FTTH closure is joint closure used in Fiber to the home network, it is used for end client with cable termination, splitting function except fusion, storage and protection. The fiber optic connectors can be SC LC with adapter brackets, and the optical splitter is steel tube, modular type from 1×2 1×4 1×8 1×16 1×32 with or without connectors. There are always round or flat cable ports with rubber seal for 2.0*3.0mm drop cable.


Joint Enclosure Structure

The joint closure fiber optic  generally consists of three parts: a cover, a base, and an internal structure, no matter it is dome splice closure or horizontal splice closure.

Dome splice closure structure
Inline splice closure structure

Splice Closure Functions

Optical performance

The remaining optical fibers in splice enclosure are coiled in the optical fiber placement device. During the installation and use of the fiber optic joint enclosure, there should be no significant additional attenuation in the optical fiber joint.

Resealing performance

The closure fiber optic shall be packaged three times according to the specified operating procedure and tested. The inflation pressure inside fiber optic splice closure is 100kPa ± 5kPa. Soak it in a clean water container at room temperature and observe steadily for 15 minutes. There should be no bubbles escaping, or the pressure gauge indication should remain unchanged after 24 hours of stable observation.

Sealing performance

After the fiber joint enclosure is sealed according to the prescribed operating procedure, the inflation pressure inside the fibre joint enclosure is (100 ± 5) kPa. Soak it in a clean water container at room temperature and observe it stably for 15 minutes. There should be no bubbles escaping, or the pressure gauge indication should remain unchanged after 24 hours of stable observation.

Mechanical properties

After the following tests, there should be no changes in the body and various parts of fiber splice case. If necessary, a light transmission inspection or opening the closure body inspection should be carried out. The following tests should be filled with (60 ± 5) kPa air pressure in fiber splice case, and the air pressure should not change after the test; Soak in a clean water container at room temperature and observe steadily for 15 minutes. There should be no bubbles escaping or no changes in the barometer indicators after 24 hours of stable observation. The shell and its components should be free from cracks, damage, and obvious deformation.

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Package Information

Yingda provides all kinds of package methods for customers, like PP bag, blister box, candy pack or others.

splice closure carton box

Cardbard Box

Individual pack with carton box, plastic bag with all accessories

splice closure carton box

Free Fumigation Pallet

Free fumigation pallets with master carton box for delivery

Spare Parts

All  splice closures are configurate with accessories to mounting or installation on site constructions, except the cover, dome, splice trays or fixture inside of the box. All accessories will be put inside of the inner pack box or with a plastic bag. 

The standard accessories will be as follow, every closure standard accessories is not the same. Additional accessories like mounting kits, air valve, grounding wire will be charge additionally.

If need to know more, please get in touch with our sales team!

FOSC 400A4 closure with standard accessories

Construction Tools May Need

When deploying cable in fiber optic communication network, there are some tools which needed to cut cable, and fusion. 

Order Information

In order to efficiently and quickly provide customers with the best quotation and solution, customers need to provide the following details in advance, thanks for your support!

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If there is a problem with the use of fiber optic fast connectors, excluding the quality of the product itself, in most cases, improper construction operations or environmental factors are the reasons.

What is an optical cable splice closure?

The fiber optic splice closure FOSC is a fiber optic passive equipment used for protective connection and fusion splice between two newborn optical fiber cables. It is a common equipment for user access points. It mainly completes the outdoor connection of optical cable distribution and home optical cables, and can be connected according to FTTX. Mini module or ABS module splitters can be installed if FAT network need.

Can you do 576 cores junction box?

Yes, we have. Yingda newly design of large capacity closure, please refer to our  model: GJS-2022ZT and GJS-2023. If this can not meet your requirements, please get in touch with our sales team, will recommend the best type for you.

What is the function of joint fiber enclosure?
  • Restoring the integrity of the optical cable sheath and the mechanical continuity of the optical cable reinforcement components.
  • Electrical connection, grounding or disconnection of metal components in optical cables.
  • Protecting fiber optic connectors from environmental influences.
  • Placing fiber connectors and storing remaining fibers.
  • Termite-proof is available on request.
Can you change the dome from mechanical to heat shrink? We want to use the same internal structure and size.

Yes, there are some models have different dome for the same closure, for example: GJS-9501B, the dome can be mechanical or heat shrink, and the cable port quantity can be changed from 10val+ 4round to 1oval+6round, 1oval+8round, or only 4round ports. 

Can we use SC adapter in the closure too?

Yes, can use SC adapters in FTTH closures, which is specially design for fiber to the home network for drop cable termination.

We only need the closure body, no need internal parts, ok?

Certainly, please indicate which spare parts do you need or no need, then we offer detail quotation for you specially.

Can your closure meet IP68?

Yes, our closures mostly can meet IP68, some meet IP67. And the FTTH closures mostly ensure meet IP65, because the drop cable ports with rubber waterproof function is not so high as cable gland or heat shrink.

If you need related test report, we can help to do the test with third party test institution.

Can you print our logo on the joint closure?

Yes, we can print your logo on the closure. There are reserved logo position on the box body. And if you have sticker request, please let us know.  We can make custom stickers/labels  on carton box and master box too.

What is the material of your closure?

Splice closure is mainly used outdoor environment, so our raw materials for closure are all brand new engineering plastic, some add glass fiber to make it more tough, all anti-UV, Anti-impact, anti-drop, anti-corrosion, anti-rat bite, anti-pressure, waterproof, etc

How long will you take to make 1000pcs 96 cores enclosure I asked?

Generally speaking, 1000pcs will take abut 7-10days to finish. If there is stock, will be shorter time. If the production line is full, will be longer, all depend on the real production line time chedule, every week the production managerment will update the time table to us, will keep you updated to arrange shipment or balance in advance. Please rest assured.

Which port is ok for you to deliver goods to?

Ningbo, Shanghai, Shenzhen port are available to make shipment. We have long term partner for shipment by sea, by air or by courier. If you dont have partner, we can offer freight cost for your reference.