Page 90 - 2010-2022 hose manufactureing ability and guide

OIL AND GASOLINE RESISTANCE

Rubber hose is used to convey petroleum In this RMA classification, the rubber samples
products both in the crude and refined stages. are immersed in IRM 903 oil at 100°C for 70
The aromatic content of refined gasoline is hours. (See ASTM Method D-471 for a detailed
often adjusted to control the octane rating. The description of the oil and the testing procedure.)
presence of aromatic hydrocarbons in this fuel As a guide to the user of hose in contact with
generally has a greater effect on rubber oil, the oil resistance classes and a
components than do aliphatic hydrocarbons. corresponding description are listed.
Aromatic materials in contact with rubber tend
to soften it and reduce its physical properties. Physical Properties After Exposure to Oil
For long lasting service, the buyer of gasoline
hose should inform the hose manufacturer of the Volume Tensile
aromatic content of the fuel to be handled so Change Strength
that the proper tube compound can be Maximum Retained
recommended for the specific application. Class A
The effects of oil on rubber depend on a (High oil resistance) +25% 80%
number of factors that include the type of rubber Class B
(Medium oil resistance) +65% 50%
compound, the composition of the oil, the Class C
temperature and time of exposure. Rubber (Limited oil resistance) +100% 40%
compounds can be classified as to their degree
of oil resistance based on their physical
properties after exposure to a standard test fluid.

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