API-936 practice question 3 of 10

[Material Requirements] Which of the following is false per the requirements of API Standard 936?

Full set: 85 questions

Domain Quality Control

Answer options
A: Cold crush strength is determined using two 4-1/2 in. (144 mm) × 4-1/2 in. (114 mm) × 4-1/2 in. (114 mm) cubes. Correct answer
B: Density shall be determined using cubes or erosion plates and linear change bars.
C: Abrasion resistance is determined using two 4-1/2 in. (114 mm) × 4-1/2 in. (144 mm) × 1 in. (25 mm) specimens.
D: Permanent linear change is determined with one 2 in. (50 mm) × 2 in. (50 mm) × 9 in. (230 mm) specimen.
Correct Answer:
A. Cold crush strength is determined using two 4-1/2 in. (144 mm) × 4-1/2 in. (114 mm) × 4-1/2 in. (114 mm) cubes.
Explanation

The statement is false. According to API Standard 936, Table 1, "Qualification Test Requirements for Monolithic Refractories," the test for Cold Crushing Strength (CCS) requires two 2 in. (50 mm) cubes. The dimensions provided in the option, 4-1/2 in. × 4-1/2 in. × 4-1/2 in., are incorrect for this specific test. Furthermore, the metric conversion provided in the option is inconsistent, listing both 144 mm and 114 mm for the same 4-1/2 in. dimension, which is an additional error.

Why Incorrect

B. This is a true statement. API 936, Section 4.3.2.2, allows density to be determined using specimens prepared for permanent linear change (bars), abrasion resistance (plates), or from cubes.
C. This is a true statement. API 936, Section 4.3.2.5, explicitly specifies that abrasion resistance shall be determined using two 4-1/2 in. × 4-1/2 in. × 1 in. (114 mm × 114 mm × 25 mm) specimens.
D. This is a true statement. API 936, Section 4.3.2.4, requires that permanent linear change be determined using one 2 in. × 2 in. × 9 in. (50 mm × 50 mm × 230 mm) specimen.

References

1. American Petroleum Institute (API). (2014). API Standard 936: Refractory Installation Quality Control—Inspection and Testing Monolithic Refractory Linings and Materials (4th ed.).

For Correct Answer (A): Table 1

"Qualification Test Requirements for Monolithic Refractories

" page 8

specifies "Two 2 in. (50 mm) cubes" for the Cold Crushing Strength test.

For Incorrect Option (B): Section 4.3.2.2

page 7

states

"Density shall be determined...using the same specimens as used for permanent linear change (see 4.3.2.4) or abrasion resistance (see 4.3.2.5)." Table 1 also lists "Two 2 in. (50 mm) cubes" for density.

For Incorrect Option (C): Section 4.3.2.5

page 7

states

"Abrasion resistance shall be determined...using two 4 1/2 in. × 4 1/2 in. × 1 in. (114 mm × 114 mm × 25 mm) specimens..."

For Incorrect Option (D): Section 4.3.2.4

page 7

states

"Permanent linear change shall be determined...using one 2 in. × 2 in. × 9 in. (50 mm × 50 mm × 230 mm) specimen..."

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