ASME B16.49-2007 pdf download.Factory-Made, Wrought Steel, Buttwelding Induction Bends for Transportation and Distribution Systems
1 SCOPE AND DEFINITIONS 1.1 General This Standard coversdesign, material,manufacturing, testing, marking, and inspection requirements for factory-made pipeline bends of carbon steel materials having controlled chemistry and mechanical properties, produced by the induction bending process, with or without tangents. This Standard covers induction bends for transportation and distribution piping applications (e.g., ASME B31.4, B31.8, and B31.11). Process and power piping have differing requirements and materials that may not be appropriate for the restrictions and examina- tions described herein and, therefore, are not included in this Standard. 1.2 Manufacturing Process This process utilizes induction heating to heat a nar- row band 360 deg around a pipe or cylinder at the point of bending as the pipe or cylinder is being pushed through the inductor coil at a constant velocity. After the material passes through the coil, it may be cooled by forced air or water spray, or it may be allowed to cool in still air. Bends in any producible wall thickness and diameter are covered. Induction bends covered by this Standard may be produced from seamless pipe, welded pipe, or cylinders. 1.3 Fabricated Bends Larger angle bends obtained by girth welding two or more smaller angle bends together are considered pipe fabrications and as such are not within the scope of this Standard. 1.4 Standard Units The values stated in either metric units or U.S. Cus- tomary units are to be regarded separately as standard. Within the text, Customary values are shown in paren- theses. The values stated in each system are not exact equivalents; therefore, each system must be used inde- pendently of the other. Combining values from two sys- tems may result in nonconformance with the standard.
1.6 Codes and Regulations A bend used under the jurisdiction of a referencing code or governmental regulation is subject to any limita- tion of that code or regulation. This includes any maxi- mum temperature limitation or rule governing the use of a material at low temperature. 1.7 Service Conditions Criteria for selection of bend material for a particular fluid service are not within the scope of this Standard. 1.8 Convention In conformance with this Standard, the convention for fixing significant digits where limits, maximum and minimum values, are specified shall be “rounded off” as defined in ASTM Practice E 29. This requires that an observed or calculated value shall be rounded off to the nearest unit in the last right-hand digit used for expressing the limit. Decimal values and tolerance do not imply a particular method of measurement. 1.9 Quality Systems Requirements relating to the manufacturers’ quality system programs are described in Nonmandatory Appendix A. 1.10 Glossary bend qualification procedure: a document that specifies the properties ofthe starting pipe; the equipmentto be used; the bending parameters; the qualification bend test results; and the postbend, heat-treat equipment and cycle used for the manufacture of the bends. If nonde- structive testing of the bend is required, procedures that have not been approved previously shall be submitted. cylinder: a jointofpipeproducedbyarollingandwelding plate, as opposed to a joint of pipe produced in accor- dance with a recognized specification.
3 SIZE The diameter of bends shall be identified by the nomi- nal pipe size (NPS) as defined in ASME B36.10M (e.g., NPS 24). Alternatively or in addition, the marking may include the nominal size as defined in ISO 6708, which consists of the letters “DN” followed by a dimensionless whole number, which is indirectlyrelated to the physical size, in millimeters, of the outside diameter of pipe to which the bend is intended to be welded (e.g., DN 600). 4 MARKING 4.1 Standard Marking Each bend shall be marked on the outside surface within 300 mm (12 in.) ofone end to show the following: (a) manufacturer’s name or trademark (b) heat number or manufacturer’s heat identification (c) material grade symbol (see para. 11.3 and Table 1) (d) B16.49 (e) nominal pipe size (NPS) (f) nominal wall thickness (g) bend radius (h) bend angle (i) postbending, heat-treatment condition (see para. 9.3) (j) supplementary requirements (if applicable) (see section SR15) Marking may be in any consistent units (metric or customary) but care shall be taken to avoid confusion. Use “X” and grade in lieu of “P” and grade for material designation for the customary stamping option.