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 40F (4C) and higher. Procedure B is for site temperatures below 40F (4C). Other suitable heat fusion joining procedures are available from various sources including pipe and fitting manufacturers. This practice does not purport to address all possible heat fusion joining procedures or 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 for PA12 fuel gas pipe per Specification F2785 and PA12 butt heat fusion fittings per Specification F1733. Consult with the pipe and fittings manufacturers to make sure they recommend this procedure for the pipe and fittings to be joined. 1.3 PA12 pipe and butt fusion fittings that are within the dimensional tolerances given in their respective ASTM specifications are required to produce sound joints when using the joining techniques described in this practice. 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 manufacturers recommendations in the use or development of a specific fusion procedure. 1.5 Units--The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. Nonconformance 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, are not exact equivalents, and are for non-mandatory informational purposes. 1.6 The text of this practice references notes, footnotes, and appendixes that provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the practice. 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 and health practices and determine the applicability of regulatory limitations prior to use.
Keywordsbutt fusion; fitting; heat fusion; joining; pipe; polyamide; PA12
Polyamide-12 pressure pipe has been extensively tested in fuel gas distribution systems and industrial pressure piping systems in the United States and other countries. ASTM International standard specifications exist for the pipe and the most frequently used appurtenances. The joining method is usually heat fusion joining. As the product comes into more frequent use and government regulators consider approval of the material and system, the need for a standard practice for fusion joining has become evident. End users and installers often ask for a standard joining method to form the basis for qualifying their personnel to join pipe. This practice will address that need.Back to Top