CWI Practical Visual Inspection 5 — Questions and Answers
Question 1: What is the maximum visual inspection distance specified by most codes for direct visual examination?
- 12 inches (300 mm)
- 24 inches (600 mm) (Correct answer)
- 36 inches (900 mm)
- 48 inches (1200 mm)
Correct answer: 24 inches (600 mm)
Most codes, including AWS D1.1, limit direct visual examination to a maximum distance of 24 inches (600 mm) from the examination surface.
Question 2: A CWI finds a crater crack at the end of a weld bead. What is the most common cause of this type of crack?
- Excessive preheat temperature during welding
- Rapid solidification and shrinkage of the molten pool when the arc is abruptly stopped (Correct answer)
- Hydrogen introduced by contaminated filler metal
- Incorrect travel angle of the electrode
Correct answer: Rapid solidification and shrinkage of the molten pool when the arc is abruptly stopped
Crater cracks form when the arc is stopped abruptly, causing the unfilled crater to shrink and crack during rapid solidification.
Question 3: When inspecting the fit-up of a butt joint before welding, the CWI should verify that the root opening is:
- As large as possible to ensure full penetration
- Within the tolerances specified by the WPS and applicable code (Correct answer)
- Zero (tight fit) to prevent burn-through
- Equal to the base metal thickness
Correct answer: Within the tolerances specified by the WPS and applicable code
Root opening must be within the tolerances of the approved WPS and code, as too little or too much opening affects penetration and fit-up quality.
Question 4: A weld inspector notices that a welder has been welding without the specified preheat. What should the inspector do?
- Allow the weld to continue and apply post-weld heat treatment afterward
- Stop welding immediately and require preheat to be established before continuing (Correct answer)
- Document the deviation and notify the engineer after welding is complete
- Increase the post-weld inspection scope
Correct answer: Stop welding immediately and require preheat to be established before continuing
Preheat is a mandatory WPS requirement; if it is not being maintained, welding must stop immediately until the required temperature is established.
Question 5: Which visual inspection technique is specifically used to detect surface-breaking discontinuities that are difficult to see with the naked eye by flooding the weld with light at a low angle?
- Direct visual inspection
- Raking (oblique) lighting technique (Correct answer)
- Transmitted light inspection
- Borescope examination
Correct answer: Raking (oblique) lighting technique
Raking or oblique lighting casts shadows from even small surface irregularities, making fine surface-breaking cracks and discontinuities more visible.
Question 6: In visual inspection, 'incomplete joint penetration' (IJP) in a full-penetration groove weld is indicated by:
- Excessive weld reinforcement on the cap
- A visible groove or unfused area along the weld root when viewed from the back side (Correct answer)
- Undercut along the weld toes
- A crack visible on the weld face
Correct answer: A visible groove or unfused area along the weld root when viewed from the back side
IJP appears as an unfused groove, channel, or void along the weld root, visible when inspected from the backside or root side of the joint.
Question 7: After completing a visual inspection and identifying a rejectable discontinuity, the CWI should:
- Verbally notify the welder and allow them to repair without documentation
- Mark the location, document the discontinuity, and issue a formal nonconformance report (Correct answer)
- Immediately grind the area and re-inspect without paperwork
- Notify the project engineer only if the defect exceeds 2 inches in length
Correct answer: Mark the location, document the discontinuity, and issue a formal nonconformance report
Any rejectable discontinuity must be formally documented with its location marked and a nonconformance report issued to initiate the repair/disposition process.
CWI Practical Visual Inspection 5
What is the maximum visual inspection distance specified by most codes for direct visual examination?