[Dec 14, 2025] API-571 Practice Exam Dumps – 99% Marks In API Exam [Q58-Q72]

NO.58 Mechanical fatigue can cause cracks that initiate from the surface and often form a:

NO.59 SOHIC is driven by localized stresses so that __________ is somewhat effective in preventing SOHIC damage.

NO.60 Type 304L SS is satisfactory for phosphoric acid concentration of 100% up to about _________. Type 321 is required from there to 225(o) F.

NO.61 Although the loss of toughness from temper embrittlement is not evident at operating temperatures, equipment that is temper embrittled may be susceptible to ________ during start-up and shutdown.

NO.62 Corrosion rates associated with hydrofluoric (HF) acid would be expected to increase if:

NO.63 Thermal fatigue cracks usually propagate _______ to the stress and they are usually dagger-shaped.

NO.64 Hydrogen blisters may form as surface bulges on the ID, the OD on within the wall thickness of a pipe or pressure vessel. Blistering occurs from hydrogen generated by ______, not hydrogen gas from the process stream.

NO.65 High temperature hydrogen attack results from exposure to hydrogen at elevated temperatures and pressures. The hydrogen reacts with __________ in steel to produce _________, which cannot diffuse through the steel. The loss of carbides causes an overall loss in strength.

NO.66 Cooling water corrosion is a concern with water-cooled __________ and cooling towers in all applications across all industries.

NO.67 Which of the following materials is susceptible to CO2 corrosion?

NO.68 There is currently no known metal alloy that is immune to _________ under all conditions.

NO.69 Stainless steel cyclones, piping ductwork and valves in high temperature FCC regeneration service are susceptible areas for _________.

NO.70 With sour water corrosion, at a given pressure, the H²S concentration in the sour water _________ as temperatures ________.

NO.71 Hydrogen blisters may form as surface bulges on the ID, the OD on within the wall thickness of a pipe or pressure vessel. Blistering occurs from hydrogen generated by ______, not hydrogen gas from the process stream.

NO.72 Alloys with nickel content above _________ are highly resistant to Cl SCC. The greatest susceptibility is 8% to
12% nickel.