Crude Oil Desalter / Dehydrator
Howe Baker designs and supplies electrostatic crude oil desalting and dehydration systems for refinery feed preparation, applying AC and DC field technology to reduce salt, water and sediment to atmospheric distillation unit specifications.
A crude oil desalter is a specific application of electrostatic coalescing technology.
The same high-voltage field principle is used across Howe Baker's electrostatic product range. For an explanation of the underlying technology, see the Electrostatic Coalescers page. The desalter adds a wash water injection and mixing step upstream of the electrostatic vessel to address residual salt removal requirements specific to refinery crude oil processing.
Crude Oil Desalting and Dehydration
After primary oil/water separation, crude oil typically contains residual dissolved salts in entrained brine that must be reduced before the crude can be processed through a refinery atmospheric distillation unit. Salt carryover causes corrosion in overhead condensing systems, fouling of preheat exchangers and accelerated equipment wear downstream.
In a desalter, clean dilution or wash water is injected into the crude oil feed through a mixing device. The dilution water contacts the residual brine droplets, distributing the salt load across a larger water volume and reducing brine concentration. The crude-water mixture then enters the electrostatic vessel, where a high-voltage AC field drives coalescence of the dispersed water droplets into larger globules that separate by gravity.
Howe Baker's custom AC3 electrode grid design uses three parallel horizontal grids within the vessel, each cross-connected to three single-phase AC power units. This arrangement creates a balanced three-phase electrical load across the full grid area. In the event of a single power unit failure, the remaining units maintain an electrostatic field throughout the vessel — the unit continues to operate at reduced capacity rather than requiring a full shutdown.
Discuss a Desalter Requirement
Speak to a Howe Baker engineer about crude desalting, dehydration or related refinery treating requirements.
Start a Project EnquiryHow the Desalter Works
Wash water injection
Clean dilution water is injected into the crude oil feed and mixed through a purpose-designed mixing device to contact and dilute brine droplets.
Crude distribution
The crude-water mixture enters the vessel through Howe Baker's internal distribution headers, which promote uniform flow across the full vessel cross-section.
Electrostatic field treatment
The mixture rises through the three-grid electrode assembly. The AC electrostatic field polarises and coalesces dispersed water droplets throughout the field volume.
Gravity separation
Coalesced water droplets grow sufficiently to overcome buoyancy and settle downward through the quiescent oil phase to a water layer at the vessel base.
Product and effluent withdrawal
Desalted crude oil is withdrawn from the vessel top. Brine is removed from the vessel base under interface-level control.
Where Crude Oil Desalters Are Used
Atmospheric Distillation Unit Feed Preparation
Desalting of crude oil to meet ADU inlet salt and water content targets. Typical industry targets are below 1 PTB salt and below 0.1 vol% BS&W at the distillation unit inlet.
Heavy and High-TAN Crude Processing
Desalting systems designed for difficult heavy crudes, high acid number crudes and blended crude slates with variable electrostatic treating characteristics requiring adapted field and chemical injection strategies.
Two-Stage Desalting
Dual-stage desalter configurations for refineries processing high-salt crude slates or requiring very low outlet salt targets. Wash water can be recovered and recycled in the two-stage configuration.
Opportunity Crude Flexibility
Desalter design optimised to handle variable crude slates from multiple sources, enabling refineries to process a wider range of opportunity crudes without compromising downstream equipment integrity.
Tight Crude and Shale Oil Treatment
Desalting of tight oil and shale crudes which present chemically stabilised emulsions requiring specialised electrical field configurations and wash water management.
Howe Baker's Engineering Role
Process and Electrical Design
Integrated process and electrical design of desalter systems including transformer-rectifier specification, electrode grid configuration, voltage profile optimisation and automatic voltage control system design.
Wash Water System Engineering
Engineering of wash water injection, mixing device selection, dilution ratio optimisation, brine water heating and effluent water management to meet treating performance targets.
Chemical Injection Systems
Design of demulsifier and scale inhibitor injection systems, chemical dosing packages and upstream injection points to address difficult emulsion chemistry.
Pressure Vessel Mechanical Design
Pressure vessel detailed design to ASME and relevant codes, including electrode assembly, internal crude distribution headers, water collection systems and all nozzle arrangements.
Control and Automation
Control system design covering desalter level, oil-water interface, transformer voltage and wash water ratio control, including integration with refinery distributed control systems.
OEM Spare Parts Supply
Supply of original equipment replacement parts for Howe Baker desalter systems — transformer-rectifier units, electrode assemblies, Teflon-bodied bushings, insulators and vessel internals.
Related Services
Desalter Spare Parts
OEM replacement transformer-rectifier units, electrode assemblies, Teflon bushings, insulators and vessel internals for Howe Baker desalter systems.
Crude Oil Desalter Services
Commissioning, performance testing, operational troubleshooting and optimisation support for installed Howe Baker desalter equipment.
Plant Revamps and Upgrades
Engineering and EPC execution for desalter capacity expansion, technology upgrade or performance improvement programmes.
Desalter references
Crude Oil Desalter System
Alberta, Canada · North America
Dual-stage electrostatic crude oil desalting for heavy oil refinery feed preparation.
Crude Desalter Package
Oman · Middle East
Single-stage electrostatic desalter for upstream field crude stabilisation.
Electrostatic Desalter
Bahrain · Middle East
Crude oil desalting unit for Middle East refinery feed treatment.
Speak to Howe Baker About This Requirement
Our engineering team can assess your crude treating and desalting requirements and advise on the most appropriate system configuration, technology and delivery model for your project.
Start a Project EnquiryRelated Solutions
Electrostatic Coalescers
The core AC and DC electrostatic separation technology behind crude oil desalting.
Distillate Treating
Electrostatic water and brine removal from kerosene, diesel and jet fuel.
Hydrocarbon Processing Systems
Integrated refinery and gas processing engineering and EPC delivery.