【国外标准】 Standard Practice for Butt Fusion Joining of PA12 Pipe and Fittings

1.1 This practice describes procedures for making butt fusion joints with Polyamide 12 (PA12) pipe and fittings by means of heat fusion joining in, but not limited to, a field environment. Procedure A is for environmental temperatures of 40 °F (4 °C) and higher. Procedure B is for site temperatures below 40 °F (4 °C). Other suitable heat fusion joining procedures are available from various sources including pipe and fitting manufacturers. This standard does not purport to address all possible heat fusion joining procedures, or to preclude the use of qualified procedures developed by other parties that have been proved to produce reliable heat fusion joints.1.2 The parameters and procedures are applicable only to joining PA12 pipe and fittings and are not applicable to other polyamide types. They are intended only for PA12 fuel gas pipe per Specification F2785 and PA12 butt heat fusion fittings in accordance with Specification F1733. Fusion to other polyamide types (that is, cross-fusion) is not permitted under this practice, and this practice does not not apply to other polyamide types. Consult with the pipe and fittings manufacturers to make sure they recommend this procedure for the pipe and fittings to be joined (also see Appendix X1).1.3 The procedures in this practice apply to the butt fusion of PA12 pipe and butt fusion fittings in accordance with 1.2 having like diameter and wall thickness.NOTE 1: Refer to X1.5 for guidance regarding dissimilar wall thicknesses.1.4 Other suitable heat joining procedures are available from various sources including pipe and fitting manufacturers. Melt characteristics, average molecular weight and molecular weight distribution of PA12 compounds are influential factors in establishing suitable fusion parameters; therefore, consider the manufacturer’s recommendations in the use or development of a specific fusion procedure.1.5 The text of this practice references notes, footnotes, and appendixes which provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the practice.1.6 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.1.6.1 Non-conformance with this specification is possible if values from the two systems are combined. Values in parentheses are conversions that are appropriately rounded for accuracy and precision; that are not exact equivalents, and that are for non-mandatory informational purposes.1.7 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.1.8 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.