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

GTAW stands for Gas Tungsten Arc Welding, commonly called TIG (Tungsten Inert Gas) welding. It uses a non-consumable tungsten electrode and a separate filler rod, shielded by an inert gas such as argon.

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

ASME IX and most company WPS documents limit root opening for a standard single-V butt weld to a maximum of 3/16 inch (4.8 mm), with typical ideal root gap being 1/16 to 1/8 inch.

Question 3

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

Accepted Answer

Inclined fixed pipe (45 degrees from horizontal)

Answer

The 6G position is a fixed-pipe position with the pipe axis inclined at 45 degrees from horizontal. It is considered the most challenging qualification position because the welder must continuously change technique as they weld around the 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

Interpass temperature maximum limits prevent the cumulative heat from multiple weld passes from raising the base and weld metal into a temperature range that causes grain coarsening and loss of impact toughness.

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

The guided bend test evaluates weld ductility and reveals discontinuities (cracks, porosity, lack of fusion, incomplete penetration) in the weld and heat-affected zone that might not be visible on the surface.

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Certified Pipefitter Practice Test

Pipefitter Welding and Joining Techniques 2