Get API-571 Exam Practice Questions - Real and Updated

Answer : A

According to API RP 571 Section 5.3.2.3 (Spheroidization):

''Spheroidization is a microstructural degradation that occurs in carbon steels and low alloy steels when exposed to elevated temperatures for long periods, typically beginning at temperatures as low as 650F (345C). It involves the transformation of lamellar pearlite into spherical cementite particles, reducing strength and hardness.''

Thus, Option A (650F / 345C) is the minimum threshold temperature for spheroidization to begin.

Answer : A

Comprehensive and Detailed Explanation From Exact Extract:

According to API RP 571 and corrosion control best practices, maximum protection of buried or soil-exposed carbon steel is achieved by combining:

A protective coating (primary barrier)

Cathodic protection (CP) (secondary, active protection)

This dual system:

Minimizes current demand

Protects coating defects

Extends service life significantly

Neither coatings nor CP alone provide equivalent long-term reliability.

Referenced Documents (Study Basis):

API RP 571 -- Section on Soil-Side Corrosion

API Corrosion Control Study Guide

Answer : D

API RP 571 states under Galvanic Corrosion:

''Because galvanic corrosion usually manifests as thinning of the more anodic metal, ultrasonic thickness measurements taken near dissimilar metal joints are an effective way to detect this type of internal corrosion.''

''Surface NDE techniques like liquid penetrant or magnetic particle testing are not effective for detecting wall loss.''

Thus, option D (ultrasonic thickness testing) is correct.

Answer : B

Comprehensive and Detailed Explanation From Exact Extract:

Amine stress corrosion cracking is most frequently associated with rich amine services, where:

Acid gas loading (HS / CO) is high

Corrosive contaminants and degradation products are present

Higher operating temperatures and stresses exist

Per API RP 571, cracking is far more common in rich amine systems than in lean amine circuits.

Why the other options are incorrect:

Lean amine has lower acid gas content and reduced SCC risk

SCC is not limited to low temperatures

Concentration alone is not the dominant factor

Referenced Documents (Study Basis):

API RP 571 -- Section on Amine Stress Corrosion Cracking

Answer : D

As per API RP 571 and further clarified in API RP 939-C:

''An arbitrary threshold of 50 ppmw HS in the aqueous phase is often used to define when carbon and low alloy steels become susceptible to cracking damage in wet HS environments.''

''Below this level, the risk of SSC, HIC, and SOHIC is considered lower, although damage has still occurred at lower concentrations depending on stress and metallurgical conditions.''

Therefore, the correct answer is option D (50 ppmw).