Equipment
Horizontal or vertical vessels separating liquids of different densities — typically oil and water. FWKO vessels take free water out upstream of treatment, reducing downstream heating, chemical-treatment and pumping duty.
Application
FWKO vessels are suited to streams where water is present as a separate phase. Stable emulsions generally require additional treating equipment.
FWKO vessels are used in conjunction with other equipment to achieve the required result, rather than as a standalone treatment step. Taking free water out early reduces the volume that has to be heated, chemically treated and pumped further down the train.
System configuration
System configuration varies with process duty, operating conditions and project requirements.

Horizontal or vertical vessel that holds the fluids long enough for free water to settle out by gravity.
Vessel dimensions, design pressure and retention time are set against your fluid properties and flow rates. Final equipment arrangement and delivery format depend on process duty, transport constraints and site requirements.
Specifications
| Variable | Effect |
|---|---|
| Retention time | The longer the fluids are held, the further the separation proceeds; this sets the vessel volume |
| Density differential of the fluids | A larger difference between oil and water drives faster gravity separation |
| Temperature of the flowing fluids | Affects viscosity and therefore how readily the phases separate |
| Parameter | Options |
|---|---|
| Orientation | Horizontal or vertical, selected against the application |
| Duty | Removal of free water upstream of treatment |
| Not suitable for | Streams where oil and water are present as an emulsion |
Vessel dimensions, design pressure and retention time are set by SPEC engineering against your fluid properties and flow rates.
Advantages
Less liquid to heat, treat and pump through the rest of the train.
No chemicals or applied field — the separation is driven by density difference and time.
Horizontal or vertical to suit the plot space and the flow regime.
Related
Vertical and horizontal separators for wellhead and inlet duty.
View →Coalescing separators removing solids and fine aerosols from gas.
View →The route where the water is bound into an emulsion.
View →Process data

Enquiries
Send us your process data and operating conditions, and we will review the duty with you.
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Engineered process equipment