TRANSFORMER
BREATHERS
FOR CONSERVATOR TANKS & OIL-FILLED TRANSFORMERS
Protect y our transformer insulating oil and critical assets from
moisture contamination with Brownell transformers breathers.
Trusted by utilities and industrial worldwide.
Why Transformer Breathers Matter
Oil-filled transformers continuously breathe as oil expands and contracts during normal operating temperatures changes. Without effective moisture control, humid air can enter the conservator tank and reduce insulating oil performances. Brownell transformer breathers remove moisture from incoming air before it enters the transformer, helping maintain oil quality, dielectric strength and long-term reliability.
Protect Transformer Oil
Prevent moisture contamination that can accelerate oil degradation and reduce transformer performance.
Maintain Dielectric Strength
Help preserve the insulating properties of transformer oil by reducing moisture ingress through the conservator system.
Protect Critical Assets
Reduce the risk of moisture-related damage to insulation systems and critical transformer components.
Extended Service Life
Support longer oil life, reduced maintenance requirements and improved transformer reliability.
Find the Right Brownell Transformer Breather
Brownell transformer breathers are available in a range of sizes and designs to suit everything from small distribution transformers to large power transformers and critical substation assets. Use the guide below to identify the most suitable breather for your application.
Brownell R Series Breathers
Distribution Transformers
Distribution transformers experience continual temperature changes which cause the conservator tank to breathe throughout the day. The Brownell R Series provides reliable moisture removal for smaller oil-filled transformers, helping maintain transformer oil quality while offering a compact, economical solution for utility and industrial applications.
✓ Compact replacement breather
✓ Ideal for distribution transformers
✓ Colour-changing Envirogel desiccant
✓ Simple refill and maintenance
✓ Cost-effective moisture protection
Brownell V, W, X Y & Z Serise
Power Transformers & Substations
Larger power transformers require increased airflow capacity whilst maintaining excellent moisture removal performance. Brownell V, W, X, Y and Z Series breathers provide higher desiccant capacity for conservator tanks serving transmission, generation and industrial power applications.
✓ Multiple capacity options
✓ Suitable for larger conservator tanks
✓ Excellent moisture removal
✓ Refillable Envirogel desiccant
✓ Designed for continuous service
Which Brownell Transformer Breather Should You Choose?
Whether you're replacing an existing transformer breather or specifying protection for a new installation, the guide below will help you identify the most suitable Brownell solution for your application.
Frequently Asked Questions
What does a transformer breather do?
A transformer breather removes moisture and airborne contaminants from the air entering an oil-filled transformer through the conservator tank. As transformer oil expands and contracts during normal temperature changes, air is drawn into and expelled from the conservator tank.
Without a breather, moisture from the atmosphere can enter the transformer, reducing the insulating properties of the oil and accelerating oxidation. Brownell transformer breathers use high-performance Envirogel silica gel to dry incoming air before it enters the transformer, helping maintain oil quality and extend equipment life.
Why do oil-filled transformers need a breather?
Oil-filled transformers rely on clean, dry insulating oil to provide both cooling and electrical insulation. During normal operation, temperature fluctuations cause the oil volume to change, resulting in the transformer "breathing".
A transformer breather prevents atmospheric moisture and airborne contamination from entering the conservator tank. By maintaining low moisture levels within the insulating oil, the breather helps reduce the risk of insulation breakdown, sludge formation and premature transformer ageing.
What is a conservator tank breather?
A conservator tank breather is installed on the air intake of a transformer's conservator tank. Every time the transformer draws air into the conservator, that air passes through the breather.
Inside the breather, colour-changing silica gel removes moisture while filters capture airborne dust and contaminants. This ensures only clean, dry air reaches the transformer oil, helping preserve the performance of both the insulating oil and cellulose insulation.
How do Brownell transformer breathers work?
Brownell transformer breathers contain Envirogel®, a premium silica gel desiccant that absorbs moisture from incoming air.
As humid air passes through the breather:
- Moisture is absorbed by the desiccant.
- Airborne particles are filtered out.
- Clean, dry air enters the conservator tank.
- The silica gel changes colour as it becomes saturated, providing a clear visual indication that maintenance is required.
This simple but highly effective process helps protect transformer oil from moisture contamination throughout its service life.
What is Envirogel® silica gel?
Envirogel® is Brownell's high-performance colour-changing silica gel designed specifically for transformer breather applications.
Unlike standard desiccants, Envirogel changes colour as it absorbs moisture, allowing maintenance personnel to quickly identify when the breather requires servicing or refilling without specialised equipment.
How often should a transformer breather be replaced or refilled?
Replacement intervals depend on several factors, including:
- Local humidity levels
- Transformer loading
- Breathing frequency
- Environmental conditions
- Breather size
Rather than replacing breathers on a fixed schedule, Brownell breathers should be inspected regularly. Once the silica gel has changed colour across most of the desiccant bed, it should be replaced or regenerated depending on the breather model.
Can transformer breathers improve transformer reliability?
Yes.
Moisture is one of the primary causes of transformer oil degradation. By preventing atmospheric moisture entering the conservator tank, Brownell transformer breathers help:
- Maintain dielectric strength
- Reduce oxidation
- Minimise sludge formation
- Protect cellulose insulation
- Extend transformer oil life
- Improve overall transformer reliability
For many operators, effective moisture control forms an important part of a predictive maintenance strategy.
Can Brownell transformer breathers replace existing transformer breathers?
In many cases, yes.
Brownell manufactures a wide range of transformer breathers suitable for replacing existing or obsolete breather models. Their range covers everything from small distribution transformers to large power transformers, making them suitable for both retrofit projects and new transformer installations.
If you're replacing an existing breather and are unsure which model you need, we can help identify a suitable Brownell equivalent.
What is the difference between a transformer breather and a desiccant tank breather?
A transformer breather is specifically designed to protect the insulating oil within oil-filled transformers by removing moisture from the air entering the conservator tank. Desiccant tank breathers, such as the Des-Case range, are used on hydraulic reservoirs, industrial gearboxes, lubricant storage tanks and other industrial equipment.
While both products use desiccant to remove moisture from incoming air, transformer breathers are engineered for the unique operating requirements of electrical transformers, whereas industrial tank breathers are designed for lubrication and hydraulic systems. If your application involves industrial machinery rather than electrical transformers, you may wish to explore our Des-Case Tank Breathers range.
