【国外标准】 Standard Test Method for Creep Relaxation of Laminated Composite Gasket Materials

4.1 This test method is designed to compare related materials under controlled conditions and their ability to maintain a given compressive stress as a function of time. A portion of the torque loss on the bolted flange is a result of creep relaxation. Torque loss can also be caused by elongation of the bolts, distortion of the flanges, and vibration; therefore, the results obtained should be correlated with field results. This test method may be used as a routine test when agreed upon between the user and the producer.1.1 This test method provides a means of measuring the amount of creep relaxation of a laminated composite gasket material at a predetermined time after a compressive stress has been applied.1.2 Creep relaxation is measured by means of a calibrated bolt with dial indicator.1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.1.4 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.