Question 1

[Installation Procedures] The mock-up for vibration cast installations demonstrates the adequacy of the: (This may have more than one correct answer; please select all that apply.)

Accepted Answer

B, C, D

Explanation: The purpose of a mock-up for vibration cast installations, as defined by API 936, is to qualify the installation procedure. This test specifically demonstrates that the proposed equipment (e.g., mixers, vibrators), the method of attaching the vibrators to the forms, and the overall vibration technique (e.g., frequency, duration, pattern) are adequate to achieve a properly consolidated refractory lining. This qualification ensures the chosen procedure can produce a dense, void-free lining consistent with the material manufacturer's requirements and project specifications before full-scale installation begins.

Question 2

[Installation Procedures] A pigment shall be used in the curing compound in order to:

Accepted Answer

D

Explanation: A pigment, or fugitive dye, is added to the curing compound to provide a distinct color that contrasts with the refractory lining. This color serves as a crucial visual aid for both the installer and the quality control inspector. It allows for immediate and easy verification that the compound has been applied uniformly across the entire surface, ensuring there are no missed spots. Complete coverage is essential for the curing compound to effectively perform its primary function of retaining moisture for proper cement hydration and strength development.

Question 3

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

Accepted Answer

A

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.

Question 4

[Documentation and Records] Who is responsible for ensuring that the material and applicator qualification test results are fully documented?

Accepted Answer

C

Explanation: According to API Standard 936, the contractor holds the primary responsibility for the quality of the refractory installation work. This scope of responsibility explicitly includes performing and fully documenting the results of both material qualification tests and applicator qualification tests. The contractor must maintain these records as part of the overall installation documentation, which is then subject to review and verification by the inspector and approval by the owner. This ensures a clear chain of accountability for the quality control process during the installation.

Question 5

DRAG DROP [Installation Procedures] Test results received from cast sample mock-ups will serve to qualify the: https://kxbjsyuhceggsyvxdkof.supabase.co/storage/v1/object/public/file-images/American_Petroleum_Institute_(API)_936/page_24_img_1.jpg

Accepted Answer

Explanation: According to API Standard 936 , the primary purpose of pre-installation testing (which includes casting sample mock-ups) is to qualify the installation procedures (the method) and the personnel (the installation crew or "fabricator") before actual work begins. The testing demonstrates that the specific combination of materials, equipment, procedures, and personnel can produce a refractory lining that meets the project specifications. Other options like "mixing time" and "mix water levels" are variables that are established, optimized, and recorded during the testing to define the procedure, but they are not the entity being "qualified" in the certification sense. The "quality of the inspection equipment" is verified through calibration, not by the mock-up itself.

Question 6

[Material Requirements] The physical attributes testing of manufactured bricks during pre-shipment testing shall require a minimum Acceptable Quality Limit (AQL) of:

Accepted Answer

B

Explanation: According to API Standard 936, the quality control requirements for manufactured refractory shapes, such as bricks, mandate specific testing protocols before installation. For physical attributes testing conducted on a lot basis, the standard explicitly defines the acceptable quality limit (AQL). This limit is set to ensure a high probability that the percentage of nonconforming items in a given lot does not exceed a specified value. The standard requires that the AQL for this type of testing shall be 4.0%.

Question 7

[Responsibilities and Qualifications] The installation contractor is required to secure an advance agreement that concerns all the installation details from the:

Accepted Answer

C

Explanation: According to API Standard 936, the installation contractor holds the primary responsibility for the satisfactory installation of the refractory lining. This responsibility is defined by the owner's specifications and drawings. To ensure alignment and prevent disputes, the standard explicitly mandates that the contractor must obtain an "advance agreement" from the owner that covers all details of the installation process. This agreement forms the contractual basis for the work and the benchmark against which the inspector will verify compliance. The owner is the ultimate client and authority for the project.

Question 8

DRAG DROP [Inspection and Testing Requirements] Which factors must be the same when retesting a sample that fails to meet specification? https://kxbjsyuhceggsyvxdkof.supabase.co/storage/v1/object/public/file-images/American_Petroleum_Institute_(API)_936/page_12_img_1.jpg

Accepted Answer

Explanation: According to API Standard 936 , when a sample fails to meet the required specifications, retesting is permitted to validate the result. To ensure the retest is scientifically valid and comparable to the original failed test, variables must be minimized. The standard explicitly states that retesting shall be performed using specimens drawn from the same batch , same pallet , and the same sample (the original quantity of material extracted) as the original test. Furthermore, the same testing procedure (methodology) must be utilized to ensure the results are correlated. Inspection methods (which typically refer to visual field monitoring or installation oversight) are distinct from the specific laboratory testing protocols and are not a variable that applies to the retesting of a specific material sample.

Question 9

[Material Requirements] What temperature is required to form a permanent bond in phosphate-bonded plastic refractory?

Accepted Answer

C

Explanation: Phosphate-bonded plastic refractories develop their permanent strength through a chemical reaction that occurs during the initial heating or dryout process. This reaction forms strong aluminum phosphate bonds. According to the American Petroleum Institute (API) Standard 936, this critical chemical bonding phase, which imparts permanent strength to the refractory before it reaches full operating temperature, occurs specifically within the temperature range of 300°F to 500°F (150°C to 260°C). Heating through this range at a controlled rate is essential to properly form the bond and drive off chemically combined water without damaging the refractory structure.

Question 10

[Inspection and Testing Requirements]
Which of the following is the appropriate term for testing refractory that was sampled during project
site installation in order to confirm that it meets specified physical property standards?

Accepted Answer

C

Explanation: As-installed testing is the correct term for the evaluation of refractory samples taken from the actual installation. This testing is performed to verify that the physical properties of the refractory material, after being mixed and applied on-site, meet the project's specified requirements. It confirms the quality of both the material and the installation workmanship, accounting for variables like water content, mixing procedure, and application technique. This is distinct from pre-qualification testing, which is done on the material before it is shipped to the site.

Question 11

[Installation Procedures]
When installing refractory castables in hot weather conditions, which of the following is acceptable?
(This may have more than one correct answer; please select all that apply.)

Accepted Answer

A, C, D

Explanation: During hot weather (ambient temperatures above 90°F [32°C]), the setting time of refractory castables is accelerated, potentially reducing working time and compromising final properties. To mitigate these effects, API 936 outlines several acceptable precautions. These include cooling the installation environment through air conditioning, preventing solar heat gain by shading equipment and the mix area, and using evaporative cooling by spraying water on the exterior of equipment like mixers. These measures help maintain the mixed castable temperature within the manufacturer's recommended limits, ensuring proper installation and curing.

Question 12

[Installation Procedures] For linings that use a surface layer of refractory plastic or a ramming mix, when should trimming, jointing, and venting be done?

Accepted Answer

B

Explanation: Trimming, jointing, and venting of refractory plastics and ramming mixes must be performed while the material is still in a workable, plastic state. These are finishing steps that must be completed "as the work progresses." If an installer waits until the material has cured or the entire installation is complete, the refractory will have hardened, making these operations difficult or impossible without damaging the lining. Therefore, these tasks must be completed on the installed section before stopping work for the day or shift, ensuring the material's integrity and proper preparation for subsequent steps or curing.

Question 13

[Material Requirements] When is metal fiber reinforcement used in castable refractory?

Accepted Answer

D

Explanation: According to API Standard 936, the inclusion of metallic or ceramic reinforcing fibers in a castable refractory is not a default requirement. It is an optional addition used to enhance specific material properties, such as toughness and resistance to thermal shock and spalling. The standard explicitly states that these fibers shall only be used when their inclusion is specified by the owner or end-user in the project's engineering design or material specifications. This ensures that the material composition is precisely tailored to the unique operational demands and potential failure modes of the specific equipment being lined.

Question 14

[Material Requirements] The quantity of manufactured refractory that has the same formulation as that prepared in an uninterrupted manufacturing operation is called a:

Accepted Answer

C

Explanation: A "production run" is the official term defined by API Standard 936 for the total quantity of a specific refractory material produced with an identical formulation during a single, continuous manufacturing operation. This ensures consistency and traceability for quality control purposes, as all material from that run is expected to have uniform physical and chemical properties. The entire batch is treated as a single lot for testing and qualification, distinguishing it from individual packaging units or samples taken from it.

Question 15

[Installation Procedures] Throughout a period of at least 24 hours, test specimens for air-setting, phosphate-bonded castable refractories are:

Accepted Answer

C

Explanation: According to API Standard 936, the specific procedure for the initial curing of test specimens for air-setting, phosphate-bonded castable refractories requires them to be air cured while uncovered. This process must last for a minimum of 24 hours at a controlled ambient temperature. This method allows the necessary chemical reaction between the phosphate bond and the aggregate to occur through interaction with the atmosphere, which is essential for developing the material's initial "green" strength before any heat is applied for dry-out.

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