MIDEL 7131
transformer fluid has a high Fire Point of 322°C
and is therefore classified as a K-class liquid (fire
point >300°C according to IEC 61100). This, coupled
with a slow heating rate due to its high specific heat
and thermal conductivity, gives the product its noted
resistance to ignition. A flawless fire safety record
of over 25 years in-service operation proves Midel to be a very safe choice
for transformers.
MIDEL 7131 is especially specified for
both indoor and outdoor transformers where the safety
of people and property could be jeopardised by fire,
such as in hospitals or in tunnels. Bunding and fire
suppression system requirements can often be reduced
with Midel filled transformers. For more details please
see below for some competitive product comparisons of
Midel versus the available alternatives.
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Mineral
oil after 1 minute. |
Mineral
oil after 3 minutes. |
Mineral
oil fully alight after 4 minutes. Note the dense
black smoke. |
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MIDEL
7131 after 3 minutes. |
MIDEL
7131 after 70 minutes. Still no ignition. |
MIDEL
7131 at 324°C finally ignites. Note very limited
emission of smoke compared to mineral oil. |
In the above ignition resistance test comparing
mineral oil and Midel, the superior fire resistance is
demonstrated very graphically. An oxy-acetylene torch
is directed onto the surface of a shallow pool of liquid
within a metal pan. The temperature of the bulk liquid
away from the surface is measured as time elapses. Many
major insurance companies, such as Factory Mutual, have
recommended Midel for its fire resistant properties.
In Germany, the ALLIANZ insurance company subjected
a Midel transformer to a test involving an external fire. Midel did not burn
and the transformer was still operable at the end of
the test. The Allianz fire test brochure can be downloaded
below.
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