Transformer Oils
Transformer Oil and the ClearGuard advantage
Our transformer oil plays a pivotal role in the reliability, efficiency, and longevity of electrical power infrastructure. At ClearGuard, we engineer transformer oils to meet the highest performance and environmental standards, offering both unused and hydrotreated solutions tailored to the demands of modern grid and industrial applications.
As the process we use is patented - and exclusively available to ClearGuard - it is the only one available in the market that can simultaneously decontaminate transformer oil and regenerate its electrical properties to a quality as good as, if not superior to, the original product.
To ensure the same levels of superior purity, we also now apply this exclusive process to our unused feedstock. This means that ClearGuard products ensure your systems run cleaner, longer, and with greater certainty.
ClearGuard Transformer Oil Range
Our Transformer Oil spans fully unused to a fully hydrotreated option, ensuring whatever your needs we can accommodate you. All our transformer oil is hydrotreated using our exclusive access to Hydrodec's patented process.
All ClearGuard oils are available in scalable formats, from railcars to barrels, with full support for implementation and ongoing lifecycle management.
To ensure we can serve all customers in all markets, our products are hydrotreated and formulated to meet or exceed different regional standards:
- Our US-market products, meeting or exceeding ASTM 3487
- Our PRO range of transformer products, meeting or exceeding IEC 60296 or CSA C50
Our high-performance products for the US market
All of our transformer oils meet or exceed ASTM 3487 specifications, either with an unused feedstock source or with a hydrotreated component, for those customers with specific ESG targets.
Customers based outside of the US market should refer to our PRO range of products.
TransGuard: our unused-based transformer oil
TransGuard™
A reliable, cost-effective mineral oil for general transformer applications. Designed for steady dielectric performance across standard operating conditions.
EcoGuard: our hydrotreated and blended oils
EcoGuard 50™
Specially designed for environmentally conscious consumers who demand a high-performing oil but are committed to reducing their carbon footprint.
EcoGuard 100™
Our 100% re-refined dielectric oil that combines high performance with sustainability. It is tailored to meet the eco-friendly needs of the energy, utilities, and industrial sectors.
Our PRO range for Canadian and European customers
Similar to our domestic market products, we have now created a range of transformer oils to meet or exceed European standard IEC 60296 and Canadian CSA C50.
For those customers that wish to have a full unused feedstock product, we have TransGuard PRO. For those customers with ESG targets we have a partial or fully hydrotreated set of products in the EcoGuard PRO range.
TransGuard PRO: our unused-based transformer oil
TransGuard PRO™
Our flagship unused transformer oil, delivering superior oxidative stability, extended service intervals, and high dielectric strength. Engineered for demanding infrastructure and mission-critical systems.
EcoGuard PRO: our hydrotreated and blended oils
EcoGuard PRO 50™
A 50/50 blend of unused and hydrotreated dielectric oils. EcoGuard PRO 50™ combines sustainability with proven performance, ideal for organizations advancing ESG targets without compromising on quality or performance.
EcoGuard PRO 100™
A 100% hydrotreated mineral oil with high moisture resistance and excellent low-temperature fluidity. EcoGuard Pro 100 offers up to 91% CO2 reduction versus traditional transformer oil: perfect for climate-aligned procurement strategies.
The uses of Transformer Oil
Transformer oil, also known as insulating or dielectric oil, serves multiple vital functions in transformers and other high-voltage equipment:
- Insulation: Prevents arcing between internal electrical components.
- Cooling: Dissipates heat generated during operation.
- Arc Suppression: Reduces the risk of internal discharge.
- Moisture Protection: Shields insulation systems from water-induced degradation.
Understanding the chemistry and behavior of transformer oil can give grid operators, engineers, and procurement leaders a vital advantage when making long-term reliability decisions.
Types of Transformer Oil
ClearGuard specializes in providing both unused-stock solutions and high-spec hydrotreated oils, enabling organizations to align operational performance with environmental priorities.
- Mineral-Based Oils – Traditional, proven, and cost-effective.
- Hydrotreated and Blended Oils – Sustainable choices that meet or exceed performance benchmarks.
Key Performance Properties
All ClearGuard transformer oils are engineered to excel across critical metrics:
- Dielectric Strength – High voltage resistance ensures safe operation under stress.
- Oxidation Stability – Prevents sludge formation and extends service life.
- Thermal Conductivity – Maintains cooling efficiency under heavy load.
- Low Moisture Content – Supports insulation integrity.
For more details on the performance specifications of our products please visit the product pages.
Maintenance & Diagnostics
Routine monitoring ensures system integrity and oil longevity:
- Dissolved Gas Analysis (DGA) – Detects early signs of insulation failure.
- Dielectric Breakdown Voltage Tests – Verifies insulation capability.
- Moisture Testing – Essential for maintaining dielectric strength.
A robust testing regimen supports both operational uptime and predictive maintenance strategies.
Circular Economy Services
Through our ClearGuard Exchange Program, customers can convert used transformer oil into operational credit while maintaining uninterrupted service:
- Scheduled Collection & Delivery
- Tested Hydrotreated Supply
- Predictable Credits & Compliance
- Zero Downtime Transitions
This closed-loop system reduces waste, simplifies logistics, and supports environmental reporting. Because of our access to Hydrodecs patented technology, this can translate into significant cost savings in transformer asset management as treated oil can be returned to service and disposal costs are avoided.
Industry Trends & Insights
- Grid Expansion & Electrification – Driving higher volumes and reliability demands.
- Sustainability Mandates – Incentivizing the switch to hydrotreated and bio-based oils.
- Smart Monitoring – Increasing adoption of oil diagnostics and predictive analytics.
ClearGuard aligns with these trends through technical innovation, environmental stewardship, and flexible delivery models.
Common Misconceptions
Are hydrotreated transformer oils less reliable?
No. When properly treated, hydrotreated transformer oils are just as reliable, if not more so, than unused oils. Our hydrotreated oils are chemically restored to a high level of purity and performance using Hydrodec’s proprietary technology. EcoGuard products consistently meet or exceed ASTM and IEC standards, delivering exceptional dielectric strength and thermal stability.
Does unused oil always outperform blends?
Not always. Performance depends more on the hydrotreated process than the source. Our EcoGuard 50 blend is engineered for stable, consistent performance in standard applications while offering a lower carbon footprint. It is an ideal mid-tier option for utilities focused on ESG targets.
Can premium oils extend equipment life?
Yes. Our premium product, TransGuard Pro, is treated through Hydrodec’s advanced hydrotreatment process to deliver superior oxidative stability, reduced sludge formation, and extended service intervals. This results in fewer oil changes, longer equipment life, and lower overall operating costs.
Technical FAQs
How is oil hydrotreated in the ClearGuard system?
We pass it through a proprietary catalytic hydrotreating process that regenerates transformer oil by deeply cleaning and transforming its molecular structure under high temperatures and pressures. This is followed by fine polishing and degassing: this advanced method removes contaminants and restructures the oil to deliver electrical properties that meet - or surpass - the original, ensuring cleaner systems, extended lifespan, and sustainable performance.
Are ClearGuard oils compatible with existing systems?
Yes. All oils are drop-in replacements, fully compliant with IEC/ASTM standards.
Do you offer full compliance documentation?
Yes. Every delivery is supported by quality certificates and regulatory alignment for emissions, sourcing, and disposal.