Dear son77jai,

I 'd advice you to qualify your welder in the 5G position for the job you are discribing. However, please refer to the QW-461.9 sec ix for further details on positions and type of weld qualified.

If you decide to qualify your welder, welding a test coupon in the 6G position it then will be qualified for welding in all positions.

The tube to tubesheet weld is a vertical weld upward or downward depending on the ability of the welder and its qualification.

By the way, the XG position is a designation for welding a test coupon. The flat, vertical, horizontal, etc, position is the designation for the position the welder is quilified and actually welding with.

Hope it helped.