Page 24 - Pipeline Pigging Technology
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Why pig a pipeline?
Fig. 2 Pigging sequence during construction.
Examples have been chosen to illustrate each application. There will, of
course, be many other variants which are covered in more specialized texts.
PIGGING DURING CONSTRUCTION
A typical sequence of events where pigs are used during pipeline construc-
tion is shown in Fig.2. The main operations are debris removal, gauging the
internal bore, cleaning off dirt, rust, and millscale, flooding the line for
hydrotest, and dewatering prior to commissioning.
Debris removal onshore
During onshore construction, it is quite possible for soil and construction
debris to find its way inside the pipeline. Such debris could wreak havoc with
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