Hola Pamekrush,
A lo mejor te sirve esta definición:

Intelligent Pigging
The purpose of intelligent pigging is to assess the condition of a metallic pipeline. By far the majority of pipeline inspection is on steel pipes with some on Ductile Iron pipe. There is a selection of pigs available to determine different aspects of pipe condition. The loss of wall thickness can be determined, lamination can be detected as can damage to a pipeline. In the majority of instances differential pressure across the pig is used to move it forwards at a controlled speed. On board intelligence records data regarding the pipelines condition and location, which can then be used to locate any faults found from ground level, following down loading of the information at a data gathering facility.
For smaller pipelines ie. 100/150 mm dia and for short lengths of pipeline a tether pig can be used. This enables live data to be transmitted via an umbilical cable from the pig to an above ground station. Conventional pigs are commonly run live, meaning whilst the pipeline is in operation. Tethered pigs are most usually used whilst the pipeline is not in use...."

Buena suerte y saludos del Oso ¶:^)

pipeline nombre tubería de distribución
     (de gas) gaseoducto
     (de petróleo) oleoducto
-- Source: Diccionario Espasa Concise © 2000 Espasa Calpe