Page 193 - Pipeline Pigging Technology

Pipeline Pigging Technology

Fig.4. Plot of debris loading vs gel train length for Phase 1.

water was approved for discharge, per EPA specifications (under a permit by
the Missouri Dept of Natural Resources). A contingency plan for filtering the
final hydrotest water through large vessels of activated carbon, or other
filtration devices, had been arranged, in case the final water did not pass the
EPA criteria for discharging, but was not necessary.
A total of 119,000gal of gel and degreaser were launched in the two phases.
It is estimated that approximately 117,000gal of material was received from
the two gellypig trains. This resulted in a material balance of 98.4%. Residual
gel, and the low amount of debris which may be present in the gel, would
easily be flushed from the pipeline during the hydrotest and drying opera-
tions.
The average velocities of the pig trains in Phase 1 and Phase 2 were
approximately 2.09 and 1.54ft/sec, respectively. These velocities are within

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