【国外标准】 Standard Test Method for Durability Testing of Duct Sealants

5.1 Residential duct systems are often field designed and assembled. There are many joints, often of dissimilar materials that require both mechanical connection and air sealing. Without this sealing, duct systems would be extremely leaky and hence inefficient. While some duct sealants are rated on their properties at the time of manufacture or during storage, none of these ratings adequately addresses the in-service lifetime. This test method has been developed to address this durability issue.5.2 This standard applies to products which list duct sealing as one of their uses. This includes duct tape (cloth, metal foil, or plastic backed), mastics, and sprayed/aerosol sealants. It does not apply to caulks or plaster patches that are not intended to be permanent duct sealing methods.5.3 The standard duct leak site is a collar to plenum connection for round duct that is 10 cm to 20 cm [4 in. to 8 in.] in diameter. This perpendicular connection was chosen because almost all residential duct systems have this type of connection and in field observations of duct systems, it is often this type of connection that has sealant failure.1.1 This test method describes an accelerated aging test for evaluating the durability of duct sealants by exposure to temperatures and static pressures characteristic of residential duct systems.1.2 This test method is intended to produce a relative measure of the durability of duct sealants. This standard does not measure durability under specific conditions of weather and building operation that might be experienced by an individual building and duct system. Instead it evaluates the sealant method under fixed conditions that do not include the manifold effects of installation practice.1.3 This test method only addresses sealants not mechanical strength of the connections.1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.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 statements see Section 7.1.6 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.