Bushings & insulators
High-pressure entrance bushing
SKU AH-EC-1001
Carries the high-voltage conductor from the transformer or power unit through the pressure boundary of a desalter, dehydrator or prewash coalescer vessel to the…
Entrance bushing
An entrance bushing is the insulated, pressure-rated feedthrough that carries the high-voltage conductor from the external transformer through the vessel wall of an electrostatic coalescer to the electrode grid. It must hold vessel pressure and insulate against full operating voltage.
high-voltage bushing
Entrance bushing explained
Bushings fail by surface tracking, by mechanical damage during installation, or where water or conductive deposits bridge the insulation. A failed bushing usually shows as a power unit that trips or will not hold voltage.
Solutions related to Entrance bushing
Electrostatic coalescers
An electrostatic coalescer is a pressure vessel that uses a high-voltage electric field to merge small water droplets in crude oil into drops large enough to…
Electrostatic coalescer prewash
An electrostatic coalescer prewash removes entrained caustic from kerosene after the caustic prewash of a kerosene sweetening unit. A high-voltage direct current (DC) field makes the…
Crude oil dehydrators
A crude oil dehydrator is an electrostatic coalescer used to remove produced water from crude so that it meets its basic sediment and water (BS&W) specification.…
Crude oil desalters
A crude oil desalter removes salt from crude by mixing in low-salinity wash water to dilute the brine, then removing the water in an electrostatic coalescer.…
Crude oil treatment
A crude oil treatment system removes water, salt and sediment so that crude meets its sales or refinery specification. It works as a train: separation, heating,…
Spare parts related to Entrance bushing
Insights and papers on Entrance bushing
A structured method for diagnosing high BS&W at a dehydrator or desalter outlet
High basic sediment and water (BS&W) at the outlet of an electrostatic dehydrator or desalter has a short list of possible causes. This paper sets out…
Glossary terms used with Entrance bushing
- Emulsion (water-in-oil)
- A water-in-oil emulsion is a dispersion of small water droplets in crude oil, held apart by natural surface-active films of asphaltenes, resins, waxes and fine solids. The droplets will not settle until those films are broken and the droplets merge.
- Electrostatic coalescence
- Electrostatic coalescence is the use of a high-voltage electric field to make small water droplets dispersed in oil collide and merge into larger droplets. Larger droplets settle much faster under gravity, so water separates from crude in a smaller vessel.
- Electrostatic coalescer
- An electrostatic coalescer is a pressure vessel with energised electrode grids, in which a high-voltage field coalesces water droplets in crude oil so they settle. Used without wash water it is a dehydrator; with wash water it is a desalter.
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