CRI CRI Pipe & Pressure Vessel Inspection 2

Question 1

What characteristic radiographic appearance distinguishes internal corrosion in a pipe from a weld discontinuity?

Accepted Answer

Corrosion appears as irregular dark areas or pitting with no sharp edges, not aligned with weld features

Answer

Internal corrosion produces irregular, diffuse dark density variations that do not align with the weld geometry and typically show a pitted or channeled pattern.

Question 2

For pressure vessel nozzle-to-shell welds, which examination technique is used when film cannot be placed inside the nozzle bore?

Accepted Answer

Double-wall single-image (DWSI) technique

Answer

DWSI technique is used for nozzle welds where film placement inside is impossible; the source is placed outside and the image of only the far-side wall is interpreted.

Question 3

A pressure vessel radiograph shows a region of lighter density (less exposure) at the edge of the weld near the nozzle junction. What is the most likely cause?

Accepted Answer

Increased material thickness at the reinforcement pad reducing radiation transmission

Answer

A reinforcement pad or extra material at a nozzle junction increases local thickness, attenuating more radiation and producing a lighter (lower density) area on film.

Question 4

Per ASME Section VIII, when is 100% radiographic examination required for pressure vessel Category A and B welds?

Accepted Answer

When the vessel is in lethal service or designed for over 1.5 times joint efficiency credit

Answer

ASME Section VIII Division 1 mandates full RT for vessels in lethal service and when the designer takes full (1.0) joint efficiency credit for weld design.

Question 5

What is the primary reason that helical (spiral) weld seams in pipe require special consideration when planning radiographic examination?

Accepted Answer

The weld angle to the pipe axis affects the projection geometry and requires angled source placement to maintain proper coverage

Answer

The helical angle of a spiral weld means a straight radiographic beam would not be perpendicular to the weld plane, requiring angled source placement to properly image the weld cross-section.

(CRI) Certified Radiographic Interpreter Practice Test

(CRI) Certified Radiographic Interpreter Practice Test

CRI CRI Pipe & Pressure Vessel Inspection 2