API 653 Material Evaluation 4

Question 1

The carbon equivalent (CE) formula is used during material evaluation primarily to assess:

Accepted Answer

Weldability and susceptibility to heat-affected zone cracking

Answer

Carbon equivalent quantifies the combined effect of alloying elements on hardenability, which directly affects weldability and HAZ cracking risk.

Question 2

During material verification of an older tank with unknown plate specifications, which field test can provide a preliminary indication of the steel grade?

Accepted Answer

Brinell hardness testing

Answer

Brinell or portable hardness testing can provide an approximate correlation to tensile strength, helping to identify unknown steel grades in the field.

Question 3

API 653 allows the use of existing shell material for fitness-for-service if it meets minimum thickness requirements, even if the original mill certification is unavailable, provided:

Accepted Answer

Chemical and mechanical tests confirm suitability

Answer

Without mill test records, API 653 requires that representative samples be tested chemically and mechanically to confirm the material meets the required specification.

Question 4

What type of non-destructive examination is most effective for detecting laminations in rolled steel plate used for tank shells?

Accepted Answer

Straight-beam ultrasonic testing (UT)

Answer

Straight-beam (compression wave) UT is sensitive to planar discontinuities parallel to the plate surface, such as laminations.

Question 5

A tank shell plate is identified as ASTM A573 Grade 70. The minimum yield strength of this material is:

Accepted Answer

42 ksi

Answer

ASTM A573 Grade 70 has a minimum tensile strength of 70 ksi and a minimum yield strength of 42 ksi.

(API 653) API 653 Aboveground Storage Tank Inspector Certification Practice Test

(API 653) API 653 Aboveground Storage Tank Inspector Certification Practice Test

API 653 Material Evaluation 4