The hot compression properties of a gasket material, including creep resistance and compression set, are a major factor with regard to the selection of a given material for use in a particular sealing application. The significance of the test method is based, in part; on the assumption that if a material exhibits too much creep at elevated temperature that it will no longer function as effectively as a seal. This assumption can only be used as a guide; however, since exact yield or failure points are difficult to define for gasket materials (which are usually viscoelastic in nature). Two or more materials can be compared to determine differences in their hot compression properties. A sample of material can be compared to an established standard or previously determined characteristics on original lots of the same material, for quality assurance purposes.

Samples are to be tested with a raised profile insert or calibration ring described in 6.3 and Fig. 1 so that the area (2042 mm² (3.17 in.²)) remains constant during the test.

FIG. 1 Test Assembly for Determining Hot Compression

1.1 This test method covers a means of measuring the hot compression properties of a gasket material by measuring its creep under a constant load at both room temperature and while increasing the temperature. Short term creep properties including both cold and hot creep, total creep and compression set of a gasket material can be determined.

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

1.3 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.