Desalters

Vessels that apply a high-voltage electric field to polarize and coalesce dispersed water droplets in the crude, accelerating brine separation. They are the dominant refinery desalting technology and are offered in AC, DC, and dual-polarity (AC/DC) field designs.

A single mixing-and-settling vessel that removes the bulk of salt and water in one pass. Suited to lighter, cleaner crudes or where moderate residual salt targets are acceptable.

Two or more desalter vessels in series, often with countercurrent wash-water routing, to achieve very low residual salt on heavy, high-salt, or opportunity crudes. The second stage polishes the partially desalted crude from the first.

Treaters configured primarily to break water-in-oil emulsions and reduce basic sediment and water (BS&W) in produced or partially refined crude. Many electrostatic vessels serve a combined dehydration and desalting duty.

Mechanical units that use centrifugal force in a rotating bowl or hydrocyclone to separate denser brine and solids from the oil phase. Used where compact, electrostatics-free separation or solids handling is preferred.

Adjustable globe or proprietary mixing valves that create the controlled pressure drop needed to disperse wash water into the crude before the settling section. Mix intensity is tuned to balance salt removal against emulsion tightness.

Electrode grids, inlet distributors, perforated headers, and interface-control internals that establish uniform flow and the electric field inside the vessel. Proper distribution is critical to coalescence efficiency and avoiding short-circuiting.

Transformers, power units, and interface-level and water-injection controls that energize the electrodes and regulate wash-water rate, mix-valve pressure drop, and oil/water interface. Modern systems use load-responsive power units to handle conductive crudes.