EOK-TORS Series – Transformer Oil Regeneration Systems

The HERING EOK-TORS transformer oil regeneration product line brings your transformer's insulating fluids back to life and restores them to their optimum condition

The growth in renewable energy production and the increase in the rating requirements for modern transformers creates a more demanding operating environment for the insulating materials. Especially, transformer insulating oil has to deal with greater electrical stresses than ever before. Therefore, the transformer oils in today’s transformers need to be at their optimum working conditions to ensure the safety of the equipment. Utility companies constantly have to maintain their transformer oil, so that it has the right dielectric strength, low residual water content, low acidity, low IFT and no sulphur.

Advanced transformer oil deterioration requires full-on transformer oil regeneration to ensure transformer safety

The transformer oil deteriorate over time as it draws in moisture and changes its chemical structure. As air slowly leaks into the transformer during its lifetime, the insulating fluid gets in contact with water and oxygen. The high temperatures during transformer operation as well as the other materials within the transformer facilitate the oxidization of the transformer oil and the cracking of the oil’s hydrocarbons. This leads to acidic components and sludge within the transformer which exponentially accelerate the oil deterioration. The acidic components attack the materials within the transformer – while the sludge severely decreases the cooling properties of the insulating fluid. Consequently, the electrical and chemical properties of the insulating fluid become worse and worse as time progresses. That is why, performing proper and timely maintenance on the transformer oil is essential to keep the transformer’s insulating system in the optimal operating range. Only then can the transformer oil successfully perform its functions of serving as a dielectric material and effective coolant.

The HERING EOK-TORS transformer oil regeneration systems give you the best of transformer oil regeneration and purification in one high-performance system

The proper treatment of transformer insulating oil involves the regeneration, dehydration and degasification of the oil. The HERING EOK-TORS transformer oil regeneration systems perform all three tasks in the highest efficient and most effective manner. Using our transformer oil regeneration equipment provides you with the all the benefits of our best-in-class EOK oil purification technology and the added power of the TORS regeneration columns. All our systems are made in Germany and powered by German Engineering to provide you with the highest quality possible.


Regeneration is 20% to 50% cheaper than new oil

Life extension with efficiency boost

Removal of corrosive sulfur (DBDS) and deterioration products

No downtime due to online & offline regenerating capabilites

The EOK-TORS transformer oil regeneration process restores your transformer oil to better-than-new condition

There are typically two ways to regenerate deteriorated transformer oil to as-new or even better-than-new state: single-use Fullers Earth regeneration and multiple-use reactivation regeneration. Our HERING EOK-TORS transformer oil regeneration plants are reactivation systems that combine higher efficiency, longer lifetime and increased flexibility when compared to single-use Fullers Earth units. The HERING EOK-TORS transformer oil regeneration systems first strain, heat and filter the oil before sending it through a series of regeneration columns. In these columns, our special highly adsorbent HERING RegenMix regeneration medium restores the oil’s properties in an initial step. Then, our HERING EOK oil purification system performs a full dehydration and degasification of the transformer oil. The quality of this process is higher than that used by most transformer oil producers. Therefore, your transformer oil will – in most cases – be restored to better-than-new conditions and at least to as-new conditions. Throughout the operation of the HERING EOK-TORS transformer regeneration system, our sophisticated reactivation process reactivates the absorbent medium in parallel to normal operation. Hence, you can use the HERING EOK-TORS to continuously regenerate transformer oil without the plant shutting down.

Do you only want a high quality oil purification plant instead? Then, our HERING EOK Series Transformer oil purification systems are the best solution for you.

Are you rather interested in full scale transformer drying ovens for a more comprehensive treatment of your transformer? Then, our HERING transformer drying oven product line might be the right choice for you.

Still not found what you were looking for? Take a look at our products page for our most popular products or get in touch for customized solutions. We will build the right product for you!