Multi-Stage PTB Cascade per GPSA §19 & API 12L
Dielectrophoresis, AC vs DC fields, refinery desalting train, sour-service materials.
Per-stage reduction factor (Manning-Thompson):
Cascade (n equal stages):
Vessel retention (per stage, half-full):
Power (empirical):
Pounds salt per thousand barrels — standard chloride-content metric for crude oil. Pipeline 5–10 PTB; refinery 1 PTB to protect overhead.
Heater treater = heat + chemical; electrostatic dehydrator adds high-voltage field to force coalescence — mandatory for heavy crude or refinery desalt spec.
RF = 1 + Vw · E_D / (1 − E_D). 2-stage typical for 50→1 PTB cascade. Single stage rarely meets refinery 1 PTB spec.