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ASME B31.3-2016 <br /> location and the minimum size of the attachment welds cover fillets having a throat dimension not less than t,. <br /> shall conform to the requirements of subpara. (i)below. The cover fillet weld shall fill and smoothly transition <br /> (c) The nomenclature and symbols used herein, in to the attachment weld and run pipe or fitting. <br /> Fig_328.5.4D, and in Fig. 328.5.4F are 328.5.5 Fabricated laps. Figure 328.5.5 shows typi- <br /> Tb = nominal thickness of branch cal fabricated laps. Fabrication shall be in accordance <br /> _Th = nominal thickness of header with the applicable requirements of para. 328.5.4. <br /> T,,, = nominal thickness of the branch weld for inte- <br /> grally reinforced branch connection fittings, 328.5.6 Welding for Severe Cyclic Conditions. A <br /> either welding procedure shall be employed that provides a <br /> (1) as specified by the manufacturer of the smooth,regular,fully penetrated inner surface. <br /> branch connection fitting <br /> (2) the full depth of the resultant weld 328.E Weld Repair <br /> groove,after fit-up,if no manufacturer's weld A weld defect to be repaired shall be removed to sound <br /> thickness is specified metal.Repair welds shall be made using a welding pro- <br /> (3) as documented and specified in the engi- cedure qualified in accordance with para.328.2.1,recog- <br /> neering design in accordance with nizing that the cavity to be repaired may differ in contour <br /> para. 300(c)(3), or and dimensions from the original joint. Repair welds <br /> (4) calculated and documented in accor- shall be made by welders or welding operators qualified <br /> _ dance with the requirements of para. 304.7.2 in accordance with para. 328.2.1. Preheating and heat <br /> T, = nominal thickness of reinforcing pad or saddle treatment shall be as required for the original welding. <br /> tc = lesser of 0.7Tb or 6 mm (1/4 in.) See also para. 341.3.3. <br /> tmi,, = lesser of Tb or T, 328.7 Attachment Welds <br /> (d) Branch connections,including branch connection Structural attachments may be made by complete pen- <br /> fittings (see paras. 300.2 and 304.3.2),that abut the out- etration,partial penetration, or fillet welds. <br /> side of the run or that are inserted in an opening in the Low energy capacitor discharge welding may be used <br /> run shall be attached by fully penetrated groove welds. for welding temporary attachments (e.g., thermocou- <br /> The welds shall be finished with cover fillet welds having ples)and permanent nonstructural attachments without <br /> a throat dimension not less than tc. See Fig. 328.5.4D, preheat above 10°C (50°F) or subsequent postweld heat <br /> illustrations (1) and (2). treatment on P-No. 1 through P-No. 5B and P-No. 15E <br /> (e) A reinforcing pad or saddle shall be attached to materials,provided <br /> the branch pipe by either (a) a Welding Procedure Specification is prepared, <br /> (1) a fully penetrated groove weld finished with a describing the low energy capacitor discharge equip- <br /> cover fillet weld having a throat dimension not less than ment,the combination of materials to be joined,and the <br /> tc, or technique of application; qualification of the welding <br /> (2) a fillet weld having a throat dimension not less procedure is not required <br /> than 0.7tmi,,. See Fig. 328.5.4D,illustration (5). (b) the energy output of the welding process is limited <br /> (f) The outer edge of a reinforcing pad or saddle shall to 125 W-sec <br /> be attached to the run pipe by a_fillet weld having a (c) for P-No. 5A,P-No. 5B, and P-No. 15E materials, <br /> throat dimension not less than 0.5T,. See Fig. 328.5.4D, the maximum carbon content of the material is 0.15% <br /> illustrations (3), (4), and (5). (d) after thermocouples are removed, the areas shall <br /> (g) Reinforcing pads and saddles shall have a good be visually examined for evidence of defects to be <br /> fit with the parts to which they are attached. A vent repaired <br /> hole shall be provided at the side (not at the crotch) of <br /> any pad or saddle to reveal leakage in the weld between 330 PREHEATING <br /> branch and run and to allow venting during welding <br /> and heat treatment. A pad or saddle may be made in 330.1 General <br /> more than one piece if joints between pieces have <br /> strength equivalent to pad or saddle parent metal,and The preheat requirements herein apply to all types of <br /> if s each piece has a vent hole. welding, including tack welds, repair welds, and seal <br /> (h) Examination and any necessary repairs of the welds on threaded joints. <br /> completed weld between branch and run shall be made 330.1.1 Requirements. Unless specified otherwise <br /> before adding a pad or saddle. in the engineering design,the minimum preheat temper- <br /> (i) Figure 328.5.4F shows additional integrally rein- atures for materials of various P-Numbers are given in <br /> forced branch connections typical of MSS SP-97 fittings Table 330.1.1. The thickness intended in Table 330.1.1 is <br /> that abut the outside of the run attached by a full pene- that of the nominal thickness of the thicker component <br /> tration groove weld. The welds shall be finished with [as defined in para.331.1.3(c)].Higher minimum preheat <br />