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Portable transformer Dry out unitOil is drawn into the high vacuum dehydration system. As oil enters the system, the inlet strainer is used to prevent particles from entering the system.

The oil is safely and efficiently heated using low watt density heaters operating at 10 - 12 watts/in2 (1.55 - 1.86 watts/cm2). The heater is thermostatically controlled to protect the oil from overheating.

The oil then enters the vacuum chamber. Vacudyne uses a unique cascading distribution plates design for the chamber. A low maintenance rotary-piston compound-vacuum pump is used to provide a deep and consistent vacuum. The vacuum chamber system provides the following benefits:

  • System vacuum less than 1 Torr
  • Vacuum pump maintains consistent vacuum and discharge volume
  • High water handling capability
  • High oil / water / gas separation due to the chamber design which includes dispersion cartridges.
  • Restores the oil dielectric strength to manufacturer's original specifications by ASTM method D1816
  • Water removal from 100 ppm to < 10 or 50 ppm to < 5 ppm
  • Gas removal from 12% by volume to less than 0.25% by volume
  • Filters 99% of particulates > 0.5 microns
  • High and low level system controls for safe operation

Oil exits the vacuum chamber by way of the outlet pump. The outlet pump enables the system to return the oil to the equipment at a consistent system flow and discharge pressure.

The oil then passes through a cartridge filter assembly. This filter is used to remove particulates down to 0.5 microns.

All high-vacuum oil purification units are supplied with a bypass valve assembly that enables the unit to also be used as a transfer system. The system also has a valve assembly that allows a portion of the oil to return to the system for additional processing. With optional control equpment the vacuum system can also be used to evacuate electrical utility equipment and restore original vacuum levels.

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  • Vacudyne's unique cascading distribution plates vacuum chamber design
  • Automated operator controls for easy use and unattended operation
  • Oil level control including high and low oil level safety shutdown
  • TEFC motors
  • Oil pump with mechanical seals
  • Low watt density heaters to aid in the removal of water
  • NEMA-12 control cabinet with operator controls
  • Outlet filter for particulate removal
  • High vacuum pump to ensure a deep consistent vacuum
  • Heavy duty carbon steel for long lasting durability
  • Oil retentive skid design for spill containment


VOPT System Options

  • PLC with touch screen
  • Fuller's earth cartridge
  • Electronic or mechanical flow meter
  • Vacuum pump upgrades
  • Hose monitors with automatic shutoff
  • Moisture analyzer
  • Foam detection and control
  • Oil trap
  • Oil inhibitor system
  • Liquid nitrogen trap
  • Inlet filter
  • Inlet pump
  • Alternate power configurations
  • And more

Trailer Options

  • Pull behind and fifth wheel
  • Air ride trailer sizes: 28', 30', 40', 45', 48', 53' (8.53m, 9.14m, 12.19m, 13.72m, 14.63m, 16.17m)
  • Multiple vacuum connections
  • Multiple door configurations
  • Various stair configurations
  • Trailer build out with work area lights, epoxy coated floor, belly-box
  • Elevated walkways with vacuum hose storage underneath
  • Office buildout with HVAC, insulation, work area, lighting, access to outside and VOPT area
  • Electric hose reel
  • Generator
  • And more


High vacuum is used for dehydration, degasification and filtration of high-voltage insulating oil. This process removes impurities and restores/improves the electrical, chemical and physical properties of the insulating oil. This system can be used on transformers, circuit breakers and switchgear/load tap changers.

Mobile & Portable Oil Filter Systems