API-571 Exam - Topic 1 Question 120 Discussion

Actual exam question for API's API-571 exam

Question #: 120
Topic #: 1

[All API-571 Questions]

Erosion and erosion-corrosion metal loss is characterized by:

Asmooth pits.

Cgrooves and gullies.

Drough pits and pock marks.

Blinear striations.

Show Suggested Answer

Suggested Answer: C

Erosion and erosion-corrosion are mechanical degradation mechanisms enhanced by fluid motion, and typically result in directional or flow-oriented metal loss patterns.

According to API RP 571 Section 5.4.2 (Erosion and Erosion/Corrosion):

''Erosion typically results in localized thinning, often described as grooves, gullies, or horseshoe-shaped patterns... The metal loss is directional and may occur in elbows, tees, reducers, and pumps.''

Hence, Option C (grooves and gullies) most accurately describes erosion and erosion-corrosion characteristics.

by Roxanne at Jan 22, 2026, 07:39 PM

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Matilda

7 hours ago

The metal loss is definitely characterized by erosion and erosion-corrosion.

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Sommer

5 days ago

I’m a bit confused about the definitions. Is erosion just the loss of material due to movement, while erosion-corrosion includes chemical reactions too?

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Levi

10 days ago

Erosion-corrosion involves both mechanical wear and chemical reactions, right? I feel like I saw a similar question in our last review session.

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Catrice

1 month ago

I remember practicing a question about the effects of velocity on erosion rates, but I can't recall the specifics on how corrosion factors in.

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Roy

1 month ago

I think erosion is mostly about the physical wear from fluid flow, but I'm not entirely sure how it differs from erosion-corrosion.

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Victor

1 month ago

This is a good opportunity to demonstrate my understanding of these material degradation processes. I'll provide a concise summary of the key characteristics that distinguish erosion from erosion-corrosion.

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Elza

2 months ago

I'm a bit unsure about the specifics here. I know erosion involves mechanical wear, but I'm not as clear on erosion-corrosion. I'll need to review my notes to make sure I can give a complete response.

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Domingo

2 months ago

Okay, I've got this. Erosion and erosion-corrosion both involve material removal, but erosion-corrosion has an additional electrochemical component. I'll outline the main features of each in my answer.

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Crissy

2 months ago

Hmm, this seems like a straightforward question, but I want to make sure I understand the key differences between erosion and erosion-corrosion. I'll need to think through the mechanisms involved.

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Cassi

2 months ago

I think this question is asking about the characteristics of erosion and erosion-corrosion metal loss. I'll need to recall what I know about those processes and how they impact materials.

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