2205 Welding Construction Acceptance Specification

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Regarding the \"Specifications for Welding Construction and Acceptance of 2205 Duplex Stainless Steel Materials\": Several questions that need to be addressed. 1. The criteria specified in clauses 9.3.1 and 9.3.2 of the standard for quantifying defects are inconsistent. Specifically: 9.3.1 Underwelding at the root – Underwelding at the root refers to underwelding that is not caused by misalignment, as shown in Figure 13. The weld is rejected if the root penetration does not meet either of the following conditions. a) Single ф508 pipe with a length exceeding 25.4 mm, any size for circumferential welds ； b) The cumulative length exceeds 25.4 mm in any continuous 304.8 mm length of the weld ； c) When the weld length is less than 304.8 mm, its cumulative length exceeds 8% of the weld length ； d) Cases where the density of the defective radiographic image exceeds that of the film from the adjacent thinner base material side. 9.3.2 Under-welding due to misalignment (IPD) Under-welding due to misalignment refers to the under-welding at the root on one side caused by the misalignment, as shown in Figure 14. The joint is unqualified when the misalignment lack of penetration meets either of the following conditions. a) Single ф508 pipe with a length exceeding 50.8m, any size for the circumferential weld ； b) The cumulative length exceeds 75 mm in any continuous 304.8 mm length of the weld ； c) When the weld length is less than 304.8 mm, its cumulative length exceeds 8% of the weld length ； d) Cases where the density of the defective radiographic image exceeds that of the film from the adjacent thinner base material side. 2. The criteria specified in Standards Clause 9.3.10 and Clause 9.7.6 for the undercut defect are inconsistent. Moreover, it is uncertain whether it is appropriate to treat the undercut defect on an equal quantitative basis as slag inclusions, lack of fusion, and incomplete penetration at the root. 9.3.10 Undercut: Undercut is a depression or groove formed by melting at the weld toe or the base metal of the weld. The part is considered non-conforming if the surface burr (EU) or internal burr (IU) meets either of the following conditions. a) In any 304.8 mm continuous length of the weld, the cumulative length of surface undercut (EU) and internal undercut (IU) in any combination exceeds 25.4 mm ； b) The cumulative length of surface undercuts (EU) and internal undercuts (IU) in any combination exceeds 1/6 of the weld length. Note: When inspecting the appearance using mechanical measuring instruments, the acceptance criteria for edge biting are specified in 9.7. 9.6.7 The undercut depth shall not exceed 0.5 mm ； Any length with a burr depth of less than 0.3 mm is considered acceptable ； The root gap depth should be between 0.3 and 0.5 mm; the length of any single gap shall not exceed 10 mm. Over any continuous length of 304.8 mm in the weld, the total length of such gaps shall not be greater than 30 mm or 10% of the total length of the weld, whichever is smaller. 3. Article 9.3.10 of the standard does not clarify whether circular defects are included in the cumulative length specified for defect accumulation. Specifically as follows: 9.3.11 Defect accumulation – In addition to undercutting and misalignment as well as incomplete welding, the product is considered non-conforming when defect accumulation meets any of the following conditions. a) In any continuous 304.8 mm length of the weld, the cumulative length of defects exceeds 50.8 mm ； b) The cumulative length of defects exceeds 8% of the weld length. 4. Article 9.5.2 of the standard does not specify a timing for the evaluation regarding circular defects. Specifically as follows: 9.5.2 Acceptance Criteria The item is considered unqualified if it meets any of the following conditions. a) Linear defects are rated as crater cracks or star-shaped cracks ； b) Linear defects of other cracks classified as non-crater or star cracks ； c) Rated as a linear defect with no surface fusion. Circular defects shall be evaluated in accordance with the provisions of 9.3.8.2 and 9.3.8.3; for evaluation, the maximum display size of the circular defect shall be used as the evaluation dimension. Note: When in doubt about the type of defect displayed, other non-destructive testing methods should be used for verification. 5. Clause 9.6.2 of the standard specifies only a lower limit for the height of defect echoes, without specifying an upper limit. Specifically as follows: 9.6.2 Weld defects For all reflectors whose reflection amplitude is 20% higher than the reference reflection amplitude, it is necessary to carefully examine them in order to determine their location, shape, size, and type, and to assess them according to the following criteria: a) Cracks of any form or size are considered unacceptable ； b) If it is classified as a non-crack opening defect, it is considered unqualified if the cumulative length of such defects over any 304.8 mm continuous length of the weld exceeds 25.4 mm, or equals 8% of the weld length ； c) Classified as a non-open defect; it is considered unacceptable if the cumulative length of such defects over any continuous 304.8 mm section of the weld exceeds 50.8 mm, or 8% of the total weld length. 6. Clause 11.3 of the standard references obsolete standards, as follows: 11.3 Liquid Penetrant Inspection Method – When the employer specifies the use of the liquid penetrant inspection method, detailed procedures for such inspection must be established, and these procedures must meet or exceed the requirements of ASTM E165 or SYJ 4043. Before flaw detection, the liquid penetrant testing procedure must be approved by the owner. 7. Clause 11.4 of the standard stipulates that flaw detection test blocks should be made of the same material (as detailed below), but it does not specify the methods for processing or manufacturing them, nor the acceptance criteria. 11.4 Ultrasonic testing methods: a) When the owner requires the use of ultrasonic testing, detailed procedures for such testing must be established, and these procedures shall meet or exceed the requirements of ASTM E164 or SY4065. The test blocks used for testing should be made of the same material. Before flaw detection, the ultrasonic flaw detection procedures must be approved by the owner. 8. Clause 9.2 of the standard stipulates that “all non-destructive testing methods have certain limitations.” If the owner believes that a certain defect’s location and depth may be detrimental to the joint’s performance, they may refuse acceptance, even though the defect meets these acceptance criteria. ”Can it be clearly stipulated or explained in writing? The owner is requested to coordinate and resolve the above issues.