S9074-AQ-GIB-010/248 Rev 1
5-6.4 POSITION AND PROGRESSION. A change to a welding position other than one already qualified (see table 7-9) or a change in progression from vertical-up to vertical-down or vice versa, except as permitted by table 7-9, footnote 9 for pipe welding. Also see 5-3.1.3 for automatic and mechanized welding. 5-6.5 JOINT DESIGN. a. In full penetration butt joints welded from one side, the omission of a backing ring or backing strip. b. In full penetration butt joints welded from one side, the omission or addition of a preplaced filler metal insert (for the welder or welding operator who makes the root pass or root pass plus an additional layer), except as permitted by table 7-10. Also, a change in the shape of the insert used. c. In tube-to-header seal weld joints for boiler components: (1) A 1/32-inch or greater decrease in root opening from that qualified. Root opening is one-half the difference between nominal tube OD and nominal counterbore size. (2) A decrease in included angle of 5 degrees or more from that qualified (any beveling of the header side of the counterbore shall also be considered as part of the weld joint included angle). However, requalification is not required for joints with angular decreases of up to 10 degrees, provided the root opening is at least 1/16 inch greater than that qualified. (3) For tube end lands 1/16 inch and less, a decrease in tube end land below that qualified. (4) An increase in counterbore depth of 1/16 inch or greater beyond that qualified, except that qualification performed on 3/16-inch deep counterbores shall qualify up to and including 1/4-inch deep counterbores. d. In full penetration butt joints, the use of a plasma arc keyhole technique for fusing the root pass. e. A change from any joint to a socket or fillet seal weld joint in piping less than 3/16 inch thick. f. A change from a fillet joint to a groove. g. A change from any joint to those addressed by 5-3.4, 5-3.5, and 5-3.6, and vice versa, except as permitted therein. A change from a lock weld joint to any other joint. 5-6.6 ACCESSIBILITY. For pipe welders, when there is a change from a condition of no restriction on joint accessibility to a condition of restricted accessibility (i.e., 12 inches or less between anything and the weld on any radial line through the weld) and the existing qualification was made under no restriction (over 12 inches). Refer to figure 7-21 for layout and construction of restricted accessibility qualification test assembly positions. 5-6.7 SHIELDING GAS. a. For gas-shielded arc welding, a change from argon, helium, or mixtures thereof to mixtures containing more than 5 percent oxygen, more than 5 percent hydrogen, or more than 25 percent carbon dioxide or to 100-percent carbon-dioxide (CO 2 ) and vice versa. Requalification for flux-cored arc welding is not required for a change from 100-percent CO 2 to an argon/CO 2 gas mixture. b. For plasma arc welding, when using the keyhole technique, a change in orifice gas from argon to mixtures of argon and helium, or the addition of hydrogen to the orifice gas or gas mixture and vice versa. c. For flux-cored arc welding, the deletion of a shielding gas. d. For torch shielding gas for S-51, S-52, S-53, and S-53A materials, a change from a single gas to any other gas or a change from a single gas to a gas mixture and vice versa. e. For S-51, S-52, S-53, and S-53A materials, a change from welding in a chamber to welding outside of a chamber. f. For trailing or backing shielding gas used for S-51, S-52, S-53, and S-53A materials when welding outside of a chamber, a change from a single gas to any other gas or a change from a single gas to a gas mixture and vice versa, or the omission of the shielding gas. g. For socket and fillet seal weld joints in piping wall thicknesses less than 3/16 inch, and consumable insert joints and one-sided full penetration joints without backing rings or consumable inserts, the deletion of backside shielding.
5-9
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