Joint Category A, Type RT-1 (full RT).
Welding of nozzle pipe are DN50 Sch160 to flange the same size.
Butt joints as attained by double‐welding or by other means that will obtain the same quality of deposited weld metal on the inside and outside weld surfaces to agree with the requirements of UW-35. Welds using metal backing strips that remain in place are excluded.
Because of small size and unable to double weld, so, do we use a single-welding with addition backing gas?