【国外标准】 Standard Practice for Preparation of Specimens and Reporting of Results for Permeance Testing of Pressure Sensitive Adhesive Sealed Joints in Insulation Vapor Retarders

5.1 PSA joints are a necessary and critical component of an insulation vapor retarder system and, in addition to knowing the permeance of the vapor retarder being used, assessing the permeance of the joints is necessary to indicate the expected performance of the system.5.2 Test Methods E96/E96M do not include instructions specific to preparing multiple-piece assemblies such as PSA joints. This practice provides those instructions.5.3 There are a number of variables involved in making a psa joint, and those need to be considered in specimen preparation and data reporting. Such variables include:5.3.1 Means of applying pressure to seal the joint,5.3.2 Amount of pressure applied,5.3.3 Dwell time prior to test,5.3.4 Backing surface upon which joint is prepared,5.3.5 Ambient conditions for specimen preparation,5.3.6 Dimensions of materials,5.3.7 Configuration of joint,5.3.8 Dish size,5.3.9 Test area of specimen, and5.3.10 Area of joint.5.4 It is not likely that field-installed joints will achieve as good a seal as those prepared in the laboratory. Field installations often involve extremes in ambient conditions, surface contamination, limited space, varying pipe radii, varying pressure applied, and variation in base insulation density and rigidity.5.4.1 Results obtained through application of this practice and Test Methods E96/E96M are best used to compare materials and configurations. It is urged not to equate actual field performance with the results obtained in a laboratory setting.1.1 This practice provides instruction for the preparation of test specimens of pressure sensitive adhesive (PSA) sealed joints of the type employed in insulation vapor retarder systems, for subsequent testing per Test Methods E96/E96M to determine the water vapor permeance (“permeance”) of those joints. It does not cover preparation of other types of joints.1.2 This practice provides requirements for the content of reports issued in conjunction with Test Methods E96/E96M testing of these joints.1.3 Joints are made with factory coated PSA tapes or PSA coated laminate jacket (vapor retarder cladding) materials.1.3.1 The types of materials and joints to be tested are generally encountered in mechanical systems in commercial and industrial insulation applications, and in HVAC systems insulation.1.3.2 Typical PSA joints that are employed in vapor retarder systems for mechanical insulation include:1.3.2.1 Overlap with double-sided tape.1.3.2.2 Overlap with coated laminate jacket.1.3.2.3 Butt with single-sided insulation tape.1.3.2.4 Intersection of overlap and butt joint.1.4 Test Methods E96/E96M are to be followed for specific testing instruction beyond the areas of guidance provided herein, that is, after the specimens are prepared in the desired test configuration.1.5 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.1.6 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.1.7 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.