Among the factors affecting shaft seal life are the ability to retain elasticity and compensate for shaft eccentricity, ability to recover from bending, and resistance to wear and the swelling effects of contact fluids. In-service testing of candidate materials is time consuming and therefore costly. Measurement of recovery from bending after exposure in fluids at elevated temperatures provides a means of quickly assessing the material’potential and acceptability for use. Comparative recovery data may then be screened and optimum performing compounds selected for further improvement or seal fabrication. It has been found that good to excellent correlation exists between a material’ability to recover from bending and sealing effectiveness.

This method is designed to measure the recovery of different rubber compounds after aging in any liquid medium, including hydraulic oils and water. This method can also be used to test rubber compounds after aging in air. Test liquids should be chosen based on the intended end use.

1.1 This test method covers a procedure to determine the recovery response of rubber after particular bending deformation, subsequent to aging in selected media at a specified temperature, and for a specified time period, thus providing a measure of the relative performance potential of compounds used in the manufacture of shaft seals.

1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.