NDT Boilermaker Structural Integrity Assessments 2

Question 1

When performing a hydrostatic pressure test on a repaired boiler, the test pressure is typically set at what multiple of the maximum allowable working pressure (MAWP)?

Accepted Answer

1.5 times MAWP

Answer

ASME code requires hydrostatic test pressure to be 1.5 times the MAWP to verify structural integrity after repair.

Question 2

Which type of weld discontinuity is MOST likely to cause stress concentration and fatigue cracking in a pressure vessel under cyclic loading?

Accepted Answer

Undercut at the weld toe

Answer

Undercut creates a notch at the weld toe that acts as a stress riser, significantly reducing fatigue life under cyclic pressure loading.

Question 3

A boiler inspector discovers a bulge on the crown sheet of a firebox. Which NDT method is BEST suited to determine the thickness remaining in the bulged area?

Accepted Answer

Ultrasonic thickness testing

Answer

Ultrasonic thickness testing can accurately measure remaining wall thickness in a bulged area without requiring access to both sides.

Question 4

In structural integrity assessments, what does the term 'fitness for service' (FFS) evaluation primarily determine?

Accepted Answer

Whether a component with a flaw can continue safe operation

Answer

Fitness for service evaluation assesses whether a component containing flaws or damage can remain in service safely until the next planned inspection.

Question 5

Which corrosion mechanism is characterized by localized attack at grain boundaries in austenitic stainless steel boiler components?

Accepted Answer

Sensitization and intergranular corrosion

Answer

Sensitization occurs when chromium carbides precipitate at grain boundaries during improper heat treatment, depleting chromium and making the material vulnerable to intergranular attack.

(NDT) Boilermaker Nondestructive Testing Certification Practice Test

(NDT) Boilermaker Nondestructive Testing Certification Practice Test

NDT Boilermaker Structural Integrity Assessments 2