Inspection Techniques & Nondestructive Testing Flashcards
7 cards from real API 510 practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Inspection Techniques & Nondestructive Testing flashcards as text
Infrared thermography (IRT) is used during pressure vessel inspection to detect:
Answer: Hot spots in refractory-lined vessels indicating lining failure or thinning
IRT detects thermal anomalies; hot spots on externally insulated or refractory-lined vessels indicate areas of lining degradation or local overheating where the protective layer has failed.
A vessel inspector conducting a radiographic examination notes 'scattered porosity' in a weld radiograph. How is scattered porosity typically evaluated per ASME Section VIII, Division 1?
Answer: It is compared against acceptance charts that consider pore size, density, and distribution
ASME acceptance criteria for porosity use charts correlating weld thickness, individual pore size, and the number of pores in a given length to determine acceptability.
During time-of-flight diffraction (TOFD) ultrasonic inspection, the lateral wave is used to:
Answer: Serve as a timing reference for calculating flaw depth and height
In TOFD, the lateral wave travels along the surface at a known velocity and serves as a precise timing reference, enabling accurate depth sizing of detected flaws.
When inspecting a pressure vessel that has experienced high-temperature hydrogen attack (HTHA), the NDT method that can detect the internal microstructural damage (methane voids and fissures) most effectively is:
Answer: Automated ultrasonic testing using creeping wave or TOFD techniques
HTHA produces internal methane-filled voids and micro-fissures that conventional methods miss; advanced UT techniques such as TOFD and creeping wave UT can detect this subsurface volumetric damage.
Per API 510, what action is required when the calculated remaining life of a pressure vessel is less than 4 years?
Answer: The next internal or on-stream inspection interval must not exceed half the remaining life
API 510 requires that when remaining life is less than 4 years, the next inspection interval shall not exceed half the remaining life to ensure the vessel is re-evaluated before reaching minimum thickness.
Positive material identification (PMI) is most critical during vessel inspection when:
Answer: Confirming that replacement materials and weld filler metals are the correct specified alloy
PMI ensures replacement components and welds use the correct alloy, preventing material mix-ups that could cause brittle fracture, stress corrosion cracking, or other failures in service.
A near-drum inspection of a pressure vessel reveals a 'turtle-back' bulge on the shell. This morphology is most characteristic of which damage mechanism?
Answer: Hydrogen-induced blistering from wet hydrogen sulfide service
Turtle-back or dome-shaped bulges on the pressure vessel shell are classic indicators of hydrogen blistering, where hydrogen atoms recombine as H₂ gas within laminations and push the metal outward.