API 510 Inspection Techniques & Nondestructive Testing 3

Question 1

Eddy current testing (ECT) is most commonly used in pressure vessel inspection for:

Accepted Answer

Inspecting heat exchanger tubes for corrosion and pitting

Answer

ECT is widely used for rapid screening of heat exchanger tubes, detecting wall loss, pitting, cracks, and support plate wear without requiring the tube to be drained.

Question 2

A vessel inspector suspects sulfide stress cracking (SSC) in a carbon steel vessel. Which NDT method is most appropriate for detecting SSC cracks at the surface?

Accepted Answer

Wet fluorescent magnetic particle testing (WFMT)

Answer

WFMT provides high sensitivity for detecting tight surface and near-surface cracks characteristic of SSC, which are typically too fine for RT to resolve reliably.

Question 3

According to API 510, the maximum interval between external inspections for a pressure vessel in normal service is:

Accepted Answer

5 years

Answer

API 510 specifies a maximum external inspection interval of 5 years for pressure vessels in normal service, though risk-based approaches may allow extensions.

Question 4

During visual inspection of the external surface of an insulated vessel, the inspector notices wet insulation at a nozzle. The primary concern is:

Accepted Answer

Corrosion under insulation (CUI) on the vessel shell and nozzle neck

Answer

Wet insulation traps moisture against the vessel surface, creating conditions for accelerated CUI, which can cause significant metal loss that is hidden under the insulation.

Question 5

Pulsed eddy current (PEC) testing offers an advantage over conventional ECT for pressure vessel inspection because it:

Accepted Answer

Can inspect through insulation and coatings without removal

Answer

PEC uses low-frequency pulsed fields that penetrate insulation and protective coatings, enabling corrosion screening without removing insulation—ideal for CUI surveys.

(API 510) API 510 Inspector Certification Practice Test

(API 510) API 510 Inspector Certification Practice Test

API 510 Inspection Techniques & Nondestructive Testing 3