Transformer Gaskets

Electrical transformer failures are often due to the ingress of moisture from the surrounding environment. The ingress of moisture and humidity into a transformer accelerates the aging process and the breakdown of insulating materials used within the transformer. Maintaining a weathertight seal through the use of effective transformer gaskets is a key requirement to extending equipment life and preventing costly failures.

When new, transformers are supplied with gaskets at all joints. These gaskets are usually made from nitrile rubber (Buna-N), which stands up well to transformer fluids, such as oil, as well as the required operating temperature range of an oi-filled transformer.

CRG services transformer gasket needs with gaskets made from Transeal TG-65 material from American Biltrite. TG-65 material produces gaskets which have superior resistance to petroleum-based hydraulic fluid. Engineered specifically for use in electrical transformers, Transeal meets or exceeds the M409E specifications. Gaskets produced from Transeal material maintain stability and help prevent dangerous transformer explosions and fires.

CRG produces transformer gaskets from Transeal TG-65 material using the latest production and fabrication technology. We can produce transformer gaskets in both large or small order volumes. Gaskets can be custom produced to suit specific transformer designs and types. We can produce transformer gaskets from Transeal TG-65 in a variety of thicknesses.

Transeal TG-65 material has a specific gravity of 1.17 and a hardness (Shore A) of 65. The material has a tensile strength of 2400 psi and an ultimate elongation percentage of 500.

Gaskets produced from Transeal TG-65 will service a cold temperature of -30°C min. Compression set for 70 hours at 100°C is 16 percent maximum, with a temperature range (general guideline) of -29°C (-20°F) to 93°C (200°F).

Heat aging for Transeal TG-65 from the ASTM D573 standard is as follows:

3 weeks @125°C

Changed hardness: 18 points

Tensile: 2% max.

Elongation: -66% max.

(all values nominal)

Oil aging (#3) from the ASTM D471 standard is as follows:

Voltesso 35 oil

Changed hardness: 3 points

Tensile: -60% max.

Elongation: -78% max.

Mass: 10%

Volume: 12%

(all values nominal)

If you are seeking premium quality transformer gaskets, our sales team will be pleased to present and discuss the advantage of CRG gaskets made from Transeal TG-65.

For further information on these products, please contact our sales department at