We enjoy hearing feedback from our customers.  A recently purchased 7 GPM Thermo-Vac Vacuum Oil Purification System was used to degas a 2500 KVA distribution transformer at a wind farm.  The transformer holds approximately 600 gallons of oil.  The High Purity Thermo-Vac Degassing System removed combustible gasses to acceptable levels in 3 hours.  Our customer expressed satisfaction in that our oil purifier accomplished the task in less half the time.  Gas reduction was more than 75%.

Additionally, moisture was < 5ppm as per Karl Fischer ASTM D-1533B.

Watch a video about our oil purifier here:

High Purity Northwest offers many options purifying transformer and other insulating oils.  These may include transformer oil filtration systems, vacuum drying and degassing.  Our systems include filtration for removing carbon and other solid contaminants.  This is important in order to achieve a dielectric strength >50 kV as per ASTM 877.

We offer portable vacuum dehydration systems and mobile oil purifiers.  Mobile systems are available on open air trailers, enclosed trailers, cargo trailers, shipping containers or large freight trailers.  We offer options such as offices, air conditioning, hose and cable storage, tool boxes, lighting and/or hose reels just to name a few.

Our insulating oil purification systems are available with single stage vacuum systems capable of pulling down to 0.5 Torr or two stage systems with vacuum pump and booster package capable of pulling down to 0.05 Torr or less.  Digital vacuum gauges are included on all Hi-Vac / high vacuum oil purification systems.

Fullers earth vessels or towers are available for acid removal to lower TAN to <0.03 KOH/g.  Typical neutralization numbers shouldn’t exceed 0.10 mg KOH/g.  Fullers earth vessels typically contain filter cartridges or bags that are thrown away when used up.  Towers or Deep Bed Filtration use slender towers that house loose clay.  Each column contains 200 to 3,000 lbs. of clay.  Flow rates of hot oil through the clay towers are 10 to 20 GPM in mobile installations and 50 GPM larger stationary systems.  Recommended oil temperature is 140-160°F.


  1. Craig Stiegemeier-Reply
    May 9, 2014 at 7:25 pm

    Did you really mean to say that the transformer met IEEE Condition 4 after the processing?

    • admin-Reply
      May 28, 2014 at 8:23 pm

      Yes. Thank you for your input. We removed this reference to alleviate any confusion.

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