Page 167 - Pipeline Pigging Technology

Pipeline Pigging Technology

Fig.2. An example of internal corrosion.

In each of the inspection operations, British Gas supplied all the launching
and receiving equipment necessary to handle the vehicles and hence perform
the operations efficiently. Three types of vehicles were run by British Gas in
the pipeline: a cleaning vehicle, profile vehicle and inspection vehicle.
The cleaning vehicle (Fig. 5) was necessary to remove large accumulations
of wax deposits from the wall of the pipe which could otherwise affect
inspection data quality. This cleaning vehicle consists basically of a magnetic
front module from an inspection train with sensors and electronics removed.
Special drive cups are fitted to the vehicle and by-pass flows can be altered to
suit line conditions.

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