ASTM D8422-21 PDF

SIGNIFICANCE AND USE 5.1 This practice has been developed to simulate the stress encountered by terminal point-of-use filters under a range of real-world use conditions with emphasis on thermal and pressure swings. Two parts, A and B, are intended to account for more frequent, less extreme use conditions and less frequent, more extreme use conditions, respectively. The purpose of pre-stressing the filters before testing by Test Method F838 is to demonstrate the ability of the filters to retain bacteria as determined by Test Method F838 after exposure to a series of temperature and pressure swings representative of those that may be encountered under actual use conditions. 5.2 This practice is not intended to account for effects on filter performance attributable to differences in the quality of the water being filtered that may be encountered under actual use conditions. 5.3 This practice is not intended to simulate the very extreme stress associated with systemic remedial procedures, such as thermal or chemical shock, sometimes implemented in premise plumbing systems. SCOPE 1.1 This practice covers terminal point-of-use (POU) filters intended for intermittent use on showers, faucets, and other water use end-point devices that deliver hot and cold potable water. 1.2 This practice does not cover in-line filters. 1.3 Units—The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 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.