Page 325 - GoodyearEPIndustrialHose

APPENDIX c
Air &
Multipurpose
General Purpose
Heavy Duty
Push-on
Chemical
Transfer
Cleaning
Equipment
Food
Transfer
Washdown
Marine
Material
Handling
Abrasives
Bulk Transfer
Cement & Concrete
Mining
Petroleum
Aircraft Fueling
Dispensing
Dock
Transfer
Spray
Steam
Vacuum
Veyance
Water
Discharge
Suction &
Discharge
Washdown
Welding
Coupling
Systems
APPENDIX
323
RMA OIL AND GASOLINE RESISTANCE
GENERAL INFORMATION
Rubber hose is used to convey petroleum products both in the crude and refined stages. The aromatic content of refined gasoline is
often adjusted to control the octane rating. The presence of aromatic hydrocarbons in this fuel generally has a greater effect on rubber
components than do aliphatic hydrocarbons. Aromatic materials in contact with rubber tend to soften it and reduce its physical
properties. For long-lasting service, the buyer of gasoline hose should inform the hose manufacturer of the aromatic content of the
fuel to be handled so that the proper tube compound can be recommended for the specific application.
The effects of oil on rubber depend on a number of factors that include the type of rubber compound the composition of the oil, the
temperature and time of exposure. Rubber compounds can be classified as to their degree of oil resistance based on their physical
properties after exposure to a standard test fluid. In this RMA classification, the rubber samples are immersed in IRM 903 oil at
100°C for 70 hours. (See ASTM Method D-471 for a detailed description of the oil and the testing procedure.) As a guide to the user
of hose in contact with oil, the oil resistance classes and a corresponding description are listed.
(Reprinted From RMA Hose
Handbook IP-2 2003 Edition)
PHYSICAL PROPERTIES AFTER EXPOSURE TO OIL
Class A (High Oil Resistance) +25% 80%
Class B (Medium Oil Resistance) +65% 50%
Class C (Limited Oil Resistance) +100% 40%
VOLUME CHANGE
MAXIMUM
TENSILE STRENGTH
RETAINED