Q. Welded Pressure Joint Requirements?

The welded pressure joint requirements should be selected to be suitable to the need; however, the following shall apply:

Welded joints of Categories A and B and, when used, butt-type Categories C and D, shall be Type No. 1.

Non-butt joints connecting nozzles (includes manways and couplings) to the vessel wall, shall be full penetration welds, with the full penetration weld being through the vessel wall and through the inside edge of reinforcing plates when used. Nozzle necks designated to extend beyond the inside surface of the vessel wall shall have a fillet weld at the inside corner.

The minimum degree of examination of welded butt joints shall be spot radiography, such that a joint efficiency not lower than 0.85 will result. In applying the rules of Par. UW-52, the increments of weld shall be selected so as to include all Category A, B, and C butt welds, except Category B or C butt welds in nozzles and communicating chambers that neither exceed NPS 10 nor 1-1/8 in (28.6 mm) wall thickness.

The need for examining the accessible surfaces of the completed Category D corner-joint welds by either the magnetic particle, liquid penetrant, ultrasonic or other nondestructive methods, shall be considered on a case-by-case basis.