What is the root opening including tolerance for a double-U-groove with partial joint penetration, welded with the SAW process, B-P7-S base metal thickness T, 3/4 min?

In a double-U-groove joint with partial joint penetration, the root opening is a critical dimension that needs to accommodate the weld metal while providing sufficient space for proper penetration and fusion of the weld. According to AWS D1.1, for a base metal thickness (T) of 3/4 inch, the root opening typically falls within a specified range based on that thickness.

For a weld made using the Sub-Arc Welding (SAW) process, the code specifies that the root opening should be proportionate. The acceptable range allows for proper weld quality aspects such as penetration and strength. With a base metal thickness of 3/4 inch, the standardized root opening typically comes out to be 1/2 inch, as it is designed to ensure that the weld can properly fill the groove and create adequate bonding strength.

This makes the correct answer valid because it aligns with the guidelines established in AWS D1.1, which are designed to promote the integrity and quality of the welded joint under structural loads.