Oil Resistant Elastomers for Hose Applications

Abstract

Abstract Since there are so many types of hose based on oil resistant elastomers and so many specifications for each type, sometimes with conflicting requirements, it is not possible to generalize regarding current uses or future trends. NBR makes up the bulk of elastomer usage for hose tubes; CR has the highest usage in covers and is used in tubes also. NBR/PVC is used in both tubes and covers. High volume usage of these polymers is expected to continue where low cost and ease of handling are paramount. When higher heat resistance is required in covers, CSM and CM are used, and the trend towards use of these is expected to continue. XNBR/PVC blends may also be used in covers when excellent abrasion resistance is required. CSM and CM may be used in tubes requiring moderate oil resistance and good heat aging. For still better heat aging, the tendency is to use ethylene-methylacrylate or silicone. When low fuel permeability is required, ECO is used; it may also be used in the cover, since it is inherently ozone resistant. The ultimate in combined fuel, oil, and heat resistance is afforded by fluoroelastomers, the use of which is increasing, where hose service requirements are particularly severe, despite their higher cost.