I have a question about the number of welds for fittings. We ordered some 44" elbows (ASTM A234-WPB). The manufacturer made them using two plates, so we have two welds on the elbows. Do they comply with ASMEB 31.3 and relevant standards?
The fabrication of your 44-inch ASTM A234 WPB elbows using two plates, resulting in two welds per elbow, is acceptable under ASME B31.3 and ASTM A234 WPB standards, provided that:
The welding procedures and welders are properly qualified according to ASME Section IX.
The welds are inspected and tested to ensure they are free from defects and meet all mechanical property requirements.
The finished fittings comply with all other applicable requirements of ASTM A234 WPB and ASME B31.3.
The standard is almost certainly ASME B 16.9. or maybe an MSS specification for the larger sizes. You need to look at those standards to confirm it and how it certifies the design.
Very large fittings are often made with two or even three seam welds so should comply with the standard without an issue.
