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ASME B31.3-2016 <br /> (16) 331.2.5 Partial Heat Treatment. When an entire pip- 332.2.2 Bending Temperature <br /> ing assembly to be heat treated cannot be fitted into the (a) Cold bending of ferritic materials shall be done at <br /> furnace,it is permissible to heat treat in more than one a temperature below the transformation range. <br /> heat, provided there is at least 300 mm (1 ft) overlap (b) Hot bending shall be done at a temperature above <br /> between successive heats,and that parts of the assembly the transformation range and in any case within a tem- <br /> outside the furnace are protected from harmful tempera- perature range consistent with the material and the <br /> ture gradients.This method may not be used for austeni- intended service. <br /> tizing heat treatments for ferritic materials. <br /> 332.2.3 Corrugated and Other Bends. Dimensions <br /> 331.2.6 Local Heat Treatment. Welds maybe locally and configuration shall conform to the design qualified <br /> postweld heat treated by heating a circumferential band in accordance with para. 306.2.2. <br /> around the entire component with the weld located in <br /> the center of the band. The width of the band heated to 332.3 Forming <br /> the specified temperature range shall be at least three The temperature range for forming shall be consistent <br /> times the wall thickness at the weld of the thickest part with material, intended service, and specified heat <br /> being joined. For nozzle and attachment welds, the treatment. <br /> width of the band heated to the specified temperature <br /> range shall extend beyond the nozzle weld or attach- 332.4 Required Heat Treatment <br /> ment weld on each side at least two times the run pipe Heat treatment shall be performed in accordance with <br /> thickness, and shall extend completely around the run para. 331.1.1 when required by the following. <br /> pipe. Guidance for the placement of thermocouples on <br /> circumferential butt welds is provided in AWS D10.10, 332.4.1 Hot Bending and Forming. After hot bend- <br /> Sections 5,6,and 8.Special consideration shall be given ing and forming,heat treatment is required for P-Nos.3, <br /> to the placement of thermocouples when heating welds 4, 5, 6, and 10A materials in all thicknesses. Durations <br /> adjacent to large heat sinks such as valves or fittings, and temperatures shall be in accordance with para.331. <br /> or when joining parts of different thicknesses. No part 332.4.2 Cold Bending and Forming. Aftercoldbend- <br /> of the materials subjected to the heat source shall exceed ing and forming,heat treatment is required(for all thick- <br /> the lower critical temperature of the material except nesses, and with temperature and duration as given in <br /> as permitted by para. 331.2.1. Particular care must be Table 331.1.1)when any of the following conditions exist: <br /> exercised when the applicable PWHT temperature is (a) for P-Nos. 1 through 6 materials,where the maxi- <br /> close to the material's lower critical temperature, such mum calculated fiber elongation after bending or form- <br /> as for P-No.15E materials or when materials of different ing exceeds 50%of specified basic minimum elongation <br /> P-Nos. are being joined. This method may not be used (in the direction of severest forming)for the applicable <br /> for austenitizing heat treatments. specification, grade, and thickness. This requirement <br /> may be waived if it can be demonstrated that the <br /> 332 BENDING AND FORMING selection of pipe and the choice of bending or forming <br /> process provide assurance that,in the finished condition, <br /> (16) 332.1 General the most severely strained material retains at least 10% <br /> Pipe may be bent and components may be formed by elongation. <br /> any hot or cold method that is suitable for the material, (b) for any material requiring impact testing, where <br /> the fluid service, and the severity of the bending or the maximum calculated fiber elongation after bending <br /> forming process.' The finished surface shall be free of or forming will exceed 5%. <br /> cracks and substantially free from buckling. Thickness (c) when specified in the engineering design. <br /> after bending or forming shall be not less than that <br /> required by the design. 333 BRAZING AND SOLDERING <br /> 332.2 Bending 333.1 Qualification <br /> 332.2.1 Bend Flattening. Flattening of a bend, the 333.1.1 Brazing Qualification. The qualification of <br /> difference between maximum and minimum diameters brazing procedures,brazers,and brazing operators shall <br /> at any cross section, shall not exceed 8% of nominal be in accordance with para.328.2.For Category D Fluid <br /> outside diameter for internal pressure and 3%for exter- Service at design temperature not over 93°C (200°F), <br /> nal pressure. Removal of metal shall not be used to such qualification is not required unless specified in the <br /> achieve these requirements. engineering design. <br /> 1 For pipe bending,PFI Standard ES-24,Pipe Bending Methods, 333.1.2 Soldering Qualification. The qualification <br /> Tolerances, Process and Material Requirements, may be used as of solderers shall be in accordance with the requirements <br /> a guide. of ASTM 13828,Standard Practice for Making Capillary <br />