Optical fibers are protected inside joint closures, also known as splice closures in the outside plant. Spliced fibers shall be protected from environmental hazards such as moisture, water, dust, soil, high temperature, ultraviolet rays etc. Environmentally sealed clsoures are joint closures that provides protection to the spliced fibers from environmental effects.
Often shorted as ESCs, Environmentally sealed closures provide all of the features and functions expected of a typical splice closure in an enclosure that prevents the intrusion of liquid and vapor into the closure interior. These features are accomplished through the use of an environmental sealing system such as rubber gaskets or hot-melt adhesives.
After installation of such closures, an ESC can be pressurized in the field to check the integrity of the environmental seal. ESCs represent the most robust environmental protection available for fiber optic closures. ESCs are generally required for deployment in the buried or underground plant and in any other deployment scenario where exposure to chemicals or corrosive agents is expected. Examples of such installation condition includes oil and gas plants, oil excavation in harbors etc.