【国外标准】 Standard Test Methods for Sealability of Gasket Materials

4.1 These test methods are designed to compare gasket materials under controlled conditions and to provide a precise measure of leakage rate.4.2 These test methods are suitable for measuring leakage rates as high as 6 L/h and as low as 0.3 mL/h. In many cases, “zero” leakage may not be attainable.4.3 These test methods evaluate leakage rates after time periods that are typically 5 to 30 min under load. Holding a gasket material under load for extended time periods may give different results.4.4 If the fluid being used in the test causes changes, such as swelling, in the gasket material, then unpredictable results may be obtained.1.1 These test methods provide a means of evaluating the sealing properties of sheet and solid form-in-place gasket materials at room temperature. Test Method A is restricted to liquid leakage measurements, whereas Test Method B may be used for both liquid and gas leakage measurements.1.2 These test methods are suitable for evaluating the sealing characteristics of a gasket material under different compressive flange loads. The test method may be used as an acceptance test when the producer and user have agreed to specific test conditions for the following parameters: test medium, internal pressure on medium, and flange load on gasket specimens.1.3 These test methods use a small-diameter narrow-width gasket as the test specimen under relatively low gasket loads and relatively low pressures. Test Method F2378 is another sealability test method that uses a larger gasket specimen and higher internal pressures and flange loads.1.4 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.1.5 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. (For specific hazard or warning statements, or both, see 5.2.11, Section 6, 6.3, 8.2.4, 11.3.2, and 11.4.2.)1.6 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.