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Buying and Storing Transformer Oil

Purchasing transformer oil is an important financial decision for your company.  It should be done very responsibly.

First, the buyer must a choose a brand of oil.  This requires careful consideration based on the type of equipment being used and the operating conditions the oil and the oil’s abilty to meet those conditions.

Second, the cost of the oil must be considered.  A small price difference in the cost of just one liter small can turn into a significant amount of money when purchasing a large volume of oil.

There are no universal recommendations for buying transformer oil. There are however, online services allowing buyers to compare transformer oil prices from various suppliers.  It is up to the buyer to research and choose a reliable wholesale distributor or retailer.

If you have already purchased transformer oil that meets the correct specifications and quality standards, then it is time to think about oil storage.

The practical way to store the oil is to use clean and dry, steel air tight vessels.  The tanks are usually coated with an oil resistant material inside.  The outside of the tanks should have anticorrosion and light reflecting coating.  The acceptable range of temperatures for storage of transformer oil is -40ºС to +60ºС/-40ºF to +140ºF.

The vessels should be equipped with valves for filling and draining as well as a manhole for cleaning, inspection and repairs.  Breathing systems must be equipped with silica gel or zeolite cartridges that can be monitored by special monitoring devices.

Three days after putting the oil into a storage tank, samples are normally taken for laboratory analysis.  Transformer oil in storage should be tested at least once a year for the following parameters:

  •  flashpoint;
  • dielectric strength at 90ºC/194ºF;
  • water extract reaction;
  • acid neutralization number;
  • particulate matter content in mircons; and
  • free water and moisture content.

It is also recommended to test the dissipation factor at 90ºС/194ºF at least once a year.

Each time the oil is tested for quality and purity, the results must comply with the parameters of fresh transformer oil regardless of the length of storage. Otherwise, the oil must be purified and regenerated to restore the oil to its new and clean condition.

GlobeCore offers a line of oil purification units under the CMM classification. These units improve color, remove acids, bases, and other aging products from any turbine, dielectric insulating oil, and industrial oils.

One of the advantages of the GlobeCore CMM line of units is their ability to regenerate oil on an energized transformer.  Another important advantage is the ability to reactive the fuller’s earth sorbent inside the unit many times over, reducing downtime for sorbent replacement and replenishment.

After the processing of transformer oil with GlobeCore equipment, transformer insulating oil is restored to an as good as new condition.

Purchasing a GlobeCore CMM unit gives you a modern efficient machine that is easy to operate and service.  The use of GlobeCore equipment and GlobeCore Process will extend the service life of the oil and the transformer significantly.