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Italy |
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New cable system design and application
Cables are responsible for providing a wide range of functions to particular applications or installations. They are often built into the infrastructure during construction and are expected to last at least as long as the infrastructure itself. This quite often means that, once installed, the cables are not readily accessible. Failure can lead to services or sections of the infrastructure being out of action while repairs are effected – which may be a long and complicated process.
In areas such as offshore platforms, there are many aspects to consider when choosing cables. First, they must be as small and light as possible, as space and weight are at a premium. Second, they must be suitably protected from the environment. This can mean a wide range of scenarios must be considered. For example: mechanical protection during installation and the cable lifetime, protection against fluids of which there are a wide variety to consider, operation in a wide range of temperatures (e.g., Sakhalin Island has temperatures from -48°C to +50°C), behavior in the event of fire, and protection against electro-magnetic interference. Finally, they must be easy to install.
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Mechanical impact performance of Airguard and CCW cables at 250 joules impact.
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The new Pirelli Airguard Cable has been designed to operate in the most extreme of environments, including offshore platforms, offering upgraded mechanical and chemical protection, in addition to having high levels of fire performance, temperature operation range and EM protection. Pirelli Energy Cables and Systems is headquartered in Milan. The new cable uses new engineering polymers, combined with a special aluminum protective layer used on traditional power cables. The benefit of using this combined technology, against traditional CCW design, is that this composite layer offers significant improvement in mechanical protection of the cable.
In addition, it provides the same level of protection against aggressive fluids such as hydrocarbons, oil, fuel, acids, bases and water. The overall composite layer is thinner and lighter than that in CCW cable and, therefore, cable dimensions are smaller. Thus, more cables can be installed in the same spaces.
The technology is applicable to low and medium voltage power cables, as well as instrumentation cables. It has been specifically designed for use in harsh environments such as offshore platforms, chemical plants, gas plants and heavy industrial factories. The technology is applicable worldwide, to AWG gauge cable sizes as well as international metric sizes. Airguard Cable is produced in Pirelli plants in Italy, Turkey and Brazil, and sold over the world.
The inner conductors (cores) of the cable are protected by a bedding material. For Airguard, two choices exist, either an extruded bedding system which completely fills the inner spaces of the cable, or polypropylene yarns, which loosely fill the spaces. In both Airguard and CCW types, the cable constructions up to this point are the same.
Over the airbag layer is a longitudinally applied coated aluminum tape which is sealed. This is then covered with a layer of engineered polymer. The combination of these two layers provides permanent protection against attack from chemicals, as noted above. In certain applications, a solid lead sheath was the only acceptable method of chemical protection. This means that the removal of lead makes the cable more environmentally acceptable.
The combined three-layer protection system is thinner and lighter than the equivalent corrugated aluminum layer in CCW cable and therefore the overall cable is smaller (about 10%) and lighter (5% to 10%) than the equivalent style CCW cable. The cable is also faster and easier to install, as it does not have the solid corrugated aluminum layer which requires special tools to cut through. This saves time and money on installation. 
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