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ASME B31.3-2016 <br /> within a specified extent of welding. For girth, miter, 344.7 In-Process Examination <br /> and branch groove welds the minimum requirement is <br /> (1) for sizes <_DN 65 (NPS 21/2), a single elliptical 344.7.1 Definition. In-process examination com- <br /> prises examination of the following, as applicable: <br /> exposure encompassing the entire weld circumference <br /> (2) for sizes>DN 65,the lesser of 25%of the inside (a) joint preparation and cleanliness <br /> circumference or 152 mm (6 in.) (b) preheating <br /> For longitudinal welds the minimum requirement is (c) fit-up,joint clearance,and internal alignment prior <br /> 152 mm (6 in.) of weld length. to joining <br /> (d) variables specified by the joining procedure, <br /> 344.6 Ultrasonic Examination including filler material <br /> (1) (for welding) position and electrode <br /> 344.6.1 Method. Examination of castings is covered (2) (for brazing) position, flux, brazing tempera- <br /> in para. 302.3.3; other product forms are not covered. ture, proper wetting, and capillary action <br /> Ultrasonic examination of welds shall be performed in (e) (for welding)condition of the root pass after clean- <br /> accordance with BPV Code,Section V,Article 4,except ing—external and,where accessible,internal—aided <br /> that the alternative specified in (a) and (b) below is by liquid penetrant or magnetic particle examination <br /> permitted for basic calibration blocks specified in when specified in the engineering design <br /> T-434.2.1 and T-434.3. (f) (for welding) slag removal and weld condition <br /> (a) When the basic calibration blocks have not between passes <br /> received heat treatment in accordance with T-434.1.5, (g) appearance of the finished joint <br /> transfer methods shall be used to correlate the responses <br /> from the basic calibration block and the component. 344.7.2 Method. The examination is visual, in <br /> Transfer is accomplished by noting the difference accordance with para. 344.2,unless additional methods <br /> between responses received from the same reference are specified in the engineering design. <br /> reflector in the basic calibration block and in the compo- <br /> nent and correcting for the difference. 345 TESTING <br /> (b) The reference reflector may be a V-notch (which <br /> must subsequently be removed), an angle beam search 345.1 Required Leak Test <br /> unit acting as a reflector,or any other reflector that will Prior to initial operation,and after completion of the <br /> aid in accomplishing the transfer. applicable examinations required by para.341,each pip- <br /> (c) When the transfer method is chosen as an alterna- ing system shall be tested to ensure tightness. The test <br /> tive,it shall be used, at the minimum shall be a hydrostatic leak test in accordance with <br /> (1) for sizes<_DN 50(NPS 2),once in each 10 welded para. 345.4 except as provided herein. <br /> joints examined (a) At the owner's option, a piping system in <br /> (2) for sizes >DN 50 and <_DN 450 (NPS 18), once Category D fluid service may be subjected to an initial <br /> in each 1.5 in (5 ft) of welding examined service leak test in accordance with para. 345.7, in lieu <br /> (3) for sizes >DN 450, once for each welded joint of the hydrostatic leak test. <br /> examined (b) Where the owner considers a hydrostatic leak test <br /> (d) Each type of material and each size and wall thick- impracticable,either a pneumatic test in accordance with <br /> ness shall be considered separately in applying the trans- para.345.5 or a combined hydrostatic-pneumatic test in <br /> fer method. In addition, the transfer method shall be accordance with para. 345.6 may be substituted,recog- <br /> used at least twice on each type of weld joint. nizing the hazard of energy stored in compressed gas. <br /> (e) The reference level for monitoring discontinuities (c) Where the owner considers both hydrostatic and <br /> shall be modified to reflect the transfer correction when pneumatic leak testing impracticable, the alternative <br /> the transfer method is used. specified in para.345.9 maybe used if both of the follow- <br /> ing conditions apply: <br /> (16) 344.6.2 Acceptance Criteria. Acceptance criteria (1) a hydrostatic test would <br /> shall be as described in (a) or (b). (a) damage linings or internal insulation <br /> (a) A linear-type discontinuity is unacceptable if the (b) contaminate a process that would be hazard- <br /> amplitude of the indication exceeds the reference level ous,corrosive,or inoperative in the presence of moisture <br /> and its length exceeds _ (c) require significant support modifications for <br /> (1) 6 mm (1/4 in.) for T,, <_ 19 mm (3/4 in.) the hydrostatic test load or <br /> (2) T,,/3 for 19 mm < T,, <_ 57 mm (21/4 in.) (d) present the danger of brittle fracture due to <br /> (3) 19 mm (3/4 in.) for Tu, > 57 mm (2%in.) low metal temperature during the test <br /> (b) The fracture mechanics ultrasonic acceptance cri- (2) a pneumatic test would <br /> teria in Appendix R may be used if all requirements of (a) present an undue hazard of possible release <br /> Appendix R are met. of energy stored in the system or <br />