How often to run a cleaning pig. Enter how fast deposits build and how much you'll allow, and get the interval between runs - by deposit thickness or by volume.
Cleaning Pig Interval
Interval = allowable buildup / deposition rate - a volume/mass balance assuming the pig scrapes the line clean each run. Guidance on the allowable side: wax dewaxing programs commonly cap buildup at about 2 mm before pigging (Tordal, PPSA Aberdeen 2006; O'Donoghue, Pipeline Research Ltd.), or roughly 50 bbl of wax, whichever your program uses; a pressure-drop or ~20% obstruction limit is the other common trigger. Get the deposition RATE from a wax/scale model or field data (rising pressure drop, weighed pig returns). For CONTINUOUS dewaxing with a bypass pig, also satisfy the continuity check Q_bypass > Q_wax so wax cannot pack ahead of the pig (O'Donoghue / PPSA). Start conservative (short interval) and lengthen it from your run returns and efficiency tests (TDW Guide to Pigging). Traces to PPSA/SPE dewaxing work - a real balance, but deposition rate is job-specific; confirm with your data.