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transformer oil purifier

The Transformer Oil Purifier / Filtration System

removes impurities and restores / improves the electrical, chemical and physical properties of transformer insulating oils. This oil is an integral part of most large power transformers.  It serves two major roles, as a cooling agent and as an electrical insulator between internal components. Contamination of this oil compromises the insulating properties and leads to premature failure of the transformer. This contamination can be in the form of water, dissolved gases, or foreign particles. By processing this oil with a vacuum dehydration unit like the Vacudyne Transformer Oil Purifier, this contamination can be removed returning the insulating oil to it’s original specifications. The system incorporates high vacuum and mechanical filtration to dehydration, degasification and filter contaminated oil. Engineered with functionality and versatility to meet a wide range of applications with features such as: an inlet pump capable of drawing oil from long distances and low elevations, a unique multi-level vacuum chamber design for rapid degasification, a sophisticated heating control scheme to insure safe and efficient processing of the contaminated oil, and a variable speed outlet pump to return the processed oil to the transformer being serviced. Control, monitoring, and user interaction is accomplished through an industrial grade touchscreen operator interface. All parameters are easily viewed and adjusted through this interface along with viewing of current and historical data.

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The Vacudyne Transformer Oil Purifier removes impurities and restores / improves the electrical, chemical and physical properties of transformer insulating oils. 

Models Includes:

  • NG Oil Purifier System (High Water Content)
  • VOP-ST - 70 gph capacity
  • VOP-1T - 100 gph capacity
  • VOP-3T - 300 gph capacity
  • VOP-6T - 600 gph capacity
  • VOP-12T - 1200 gph capacity
  • VOP-18T - 1800 gph capacity
  • VOP-24T - 2400 gph capacity
  • VOP-30T - 3000 gph capacity
  • VOP-40T - 4000 gph capacity



Models Typically include:

  • Vacudyne's unique multi level vacuum chamber design
  • Automated control system for ease of use and unattended operation
  • Intuitive display of vacuum, pressure, temperature and filter conditions
  • Easy access to all operating parameters
  • Built-in logging buffer for historical informaiton retrieval
  • Electronic flow meter with lifetime and user resettable displays
  • VFD pump drives
  • Oil level control including high and low oil level safety shutdown
  • Multi-stage foam control for optimal processing
  • TEFC motors
  • Oil pump with single mechanical seals
  • Low watt density heaters to aid in water removal
  • NEMA 12 control and power cabinets
  • Inlet and outlet filters for particulate removal
  • Booster / backer vacuum pump to ensure a deep consistent vacuum
  • Thermostatically controlled heater with selectable capacity
  • Heavy duty rigid steel construction for long lasting durability
  • Oil retentive skid design for spill containment


  • Flow capabilities from 70 GPH to over 4000 GPH
  • Mobile configuration (enclosed trailer) 
  • Fuller's earth cartridge
  • Remote monitoring
  • Vacuum pump upgrades
  • Hose monitors with automatic shutoff
  • Moisture analyzer
  • Oil trap with level sensor
  • Oil inhibitor system
  • Liquid nitrogen trap
  • Particulate analyzer
  • Alternate power configurations
  • NEMA 4 control and power cabinets
  • Additional Options available, contact us with your specific needs


  • Transformer Insulating Oil
  • Switchgear Insulating Oil
  • Load Tap Changer Insulating Oil
  • Other liquid applications requiring the removal of impurities and restoration


Water Removal: 100 ppm to < 5 ppm by ASTM method D1533
Total Gas Content: 12% to < 0.25% by volume by ASTM method D2945
Particulate Removal: Filters 99% of particulates ≥ 0.5 microns
Dielectric Strength: Restores the oil dielecric strength to manufacturer's original specification by ASTM method D1816


Click Here for Oil Purifier Specifications

Transformer Oil Purifier