Pipefitter Welding and Joining Techniques 2

Question 1

What welding process is designated by AWS process abbreviation GTAW?

Accepted Answer

Gas tungsten arc welding (TIG)

Answer

Gas metal arc welding (MIG)

Answer

Flux-cored arc welding

Answer

Shielded metal arc welding (Stick)

Question 2

What is the maximum allowable root opening (gap) for a single-V butt weld in pipe per typical ASME Section IX workmanship requirements?

Accepted Answer

3/16 inch (4.8 mm)

Answer

1/16 inch (1.6 mm)

Answer

1/4 inch (6.4 mm)

Answer

3/8 inch (9.5 mm)

Question 3

When welding in the 6G position, what does the '6' indicate?

Accepted Answer

Inclined fixed pipe (45 degrees from horizontal)

Answer

6-inch pipe diameter

Answer

Horizontal fixed pipe

Answer

Vertical fixed pipe

Question 4

What is the purpose of an interpass temperature limit during multi-pass welding of alloy steel?

Accepted Answer

To prevent overheating the base metal, which can cause grain coarsening and reduction in toughness and creep strength

Answer

To ensure the weld pool stays molten between passes

Answer

To keep the welder from burning the rod too fast

Answer

To maintain the pipe at preheat temperature throughout

Question 5

What is the primary purpose of a weld coupon bend test in ASME Section IX welder qualification?

Accepted Answer

Evaluate weld ductility and detect surface and subsurface discontinuities in the weld and HAZ

Answer

Measure the weld's tensile strength only

Answer

Measure the weld bead width and reinforcement

Answer

Test the weld for pressure tightness

Question 6

In threaded pipe connections, what type of sealant is used on a steam service line?

Accepted Answer

Thread sealant compound rated for high-temperature steam service (e.g., Rectorseal No. 5 or equivalent)

Answer

PTFE (Teflon) tape only

Answer

No sealant is needed; steam connections seal by thread engagement alone

Answer

Standard petroleum-based pipe dope