API Exam API-571 Topic 1 Question 111 Discussion

Actual exam question for API's API-571 exam

Question #: 111
Topic #: 1

A carbon steel bundle from the overhead condenser in the crude unit operates at 300 F and is in hydrochloric acid service. It showed severe pitting type corrosion when pulled for inspection. What type of material would be best suited for this service?

A5Cr-0.5Mo

B316 stainless steel

C9Cr-1Mo

DTitanium

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Suggested Answer: D

by Carlene at Jun 14, 2025, 02:17 PM

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Belen

4 days ago

I'm going with 316 stainless steel. It's a classic choice for corrosive services and should hold up well to the pitting issues. Just hope the cost doesn't blow the budget!

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Carey

9 days ago

Titanium is a great option here. It's highly resistant to pitting and crevice corrosion, even in aggressive acid environments. Plus, it's lightweight and easy to fabricate.

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Pete

12 days ago

Why do you think 9Cr-1Mo is better?

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Theodora

23 days ago

I think 9Cr-1Mo would be the best choice for this application. The high chromium content provides good corrosion resistance in hydrochloric acid, and the molybdenum addition further enhances the corrosion protection.

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