Aramco CBT Exam Questions for Welding QC Inspector

This article is about Welding Aramco CBT Exam Questions for Welding QC Inspector as per International codes and standards.

1. What are the SAES specs for hydro testing?

The SAES (Saudi Aramco Engineering Standards) specifications for hydro testing include:

SAES-A-004: General Requirements of Pressure Testing: This specification provides general guidelines and requirements for conducting pressure testing of equipment and systems. It covers various aspects such as test procedures, equipment preparation, safety considerations, and documentation.
SAES-A-007: Hydrostatic Testing Fluids and Lay-Up Procedure: This specification outlines the requirements for hydrostatic testing fluids used in pressure testing. It covers the selection, preparation, and disposal of testing fluids. Additionally, it includes guidelines for the lay-up procedure after the completion of hydro testing to prevent corrosion or damage to the equipment.
SAES-L-150: Pressure Testing of Plant Piping & Pipelines: This specification specifically focuses on pressure testing of plant piping and pipelines. It provides detailed requirements for test pressure, duration, equipment setup, inspection, and acceptance criteria for ensuring the integrity and safety of the tested systems.

2) What is a dead leg?

A dead leg refers to a section of piping that has limited or no flow, resulting in flow stagnation. It is a potential area of concern in industrial piping systems due to the increased risk of internal corrosion. Dead legs are typically formed when there is flow stagnation combined with the presence of settled water and solid deposits.

The length of a section or branch is an important factor. For pipes with a diameter of 2 inches or larger, if the length of the section or branch is longer than three times its pipe diameter or exceeds 1.22 meters (4 feet), it is considered a dead leg. The length of the dead leg is measured from the outside diameter of the header (or run) to the near end of the branch valve.

For branch connections with a size of 1-½ inch NPS (Nominal Pipe Size) and smaller, the length of the dead leg is measured from the end of the boss to the near end of the valve.

Identifying and managing dead legs is crucial in maintaining the integrity and reliability of piping systems, as they can contribute to internal corrosion and the accumulation of deposits. Proper design considerations and regular inspection and maintenance are necessary to mitigate the potential risks associated with dead legs.

3) What are the different ASME B31 codes for pressure piping?

The ASME B31 codes are a series of standards that provide guidelines for the design, construction, inspection, and maintenance of different types of pressure piping systems. The following are the ASME B31 codes relevant to specific types of pressure piping:

A. ASME B31.1 – Power Piping: This code covers piping systems used in power generation plants, including fossil fuel, nuclear, and solar power plants.

B. ASME B31.2 – Fuel Gas Piping: This code addresses piping systems used for the transportation and distribution of fuel gases, such as natural gas and propane.

C. ASME B31.3 – Process Piping: This code applies to piping systems used in chemical plants, refineries, and other processing facilities where fluids or gases are processed, transported, or stored.

D. ASME B31.4 – Pipeline Transportation Systems for Liquid Hydrocarbons and Other Liquids: This code focuses on the design, construction, and maintenance of piping systems used in the transportation of liquid hydrocarbons, including crude oil and petroleum products.

E. ASME B31.5 – Refrigeration Piping: This code covers the design, construction, and maintenance of piping systems used in refrigeration and cooling applications, including industrial refrigeration, HVAC systems, and cryogenic systems.

F. ASME B31.8 – Gas Transmission and Distribution Piping Systems: This code pertains to piping systems used for the transmission and distribution of natural gas and other gases, including both onshore and offshore pipelines.

G. ASME B31.9 – Building Services Piping: This code applies to piping systems used in buildings for various services, including heating, cooling, and utility distribution.

H. ASME B31.11 – Slurry Transportation Piping Systems: This code addresses the design and construction of piping systems used for the transportation of solid-liquid mixtures, known as slurries.

4) What are the factors included in a mill test certificate?

A mill test certificate, also known as an MTC or a material test report (MTR), provides important information about the material used in a specific product, such as pipes, plates, or bars. The following factors are typically included in a mill test certificate:

Chemical Composition: The mill test certificate specifies the chemical composition of the material, including the percentages of different elements present.
Mechanical Properties: It provides information about the mechanical properties of the material, such as hardness, tensile strength, yield strength, elongation, and reduction of area. These properties indicate the material’s strength and ductility.
Heat Number: The mill test certificate includes a unique heat number that identifies the specific batch or lot of material used. This number helps trace the material back to its production process and raw material sources.

The mill test certificate is an essential document for ensuring the quality and compliance of materials used in various applications. It provides valuable information that helps verify the material’s conformance to specified standards and requirements.

5) What type of rope is commonly used for lifting external coated pipes?

Answer: Nylon ropes are commonly used for lifting external coated pipes.

6) What is the minimum clearance required between a pipe and a structure?

Answer: The minimum clearance required between a pipe and a structure is typically 50mm.

7) How long is the holding time for hydro testing A/G (above ground) piping?

Answer: The holding time for hydro testing A/G piping is typically 30 minutes.

8) During flange alignment fit-up, what are the important activities that need to be checked?

Answer: During flange alignment fit-up, the following activities should be checked:

Misalignment
Flange face condition
Rotation of flanges (±2.4 mm)
Tilt of the flange (should not exceed 1.6 mm from the square position)
Flange face thickness and gasket thickness (±1.6 mm)
Combination of vertical, horizontal, and rotational offsets (±3.2 mm)

9) What are the responsibilities of a piping inspector?

Conduct material receiving inspection.
Ensure that approved procedures and Inspection Test Plans (ITPs) are followed during construction.
Oversee pipe fit-up activities.
Maintain records and reports related to quality control.
Perform line checking to ensure compliance with specifications.
Supervise hydro test activities.
Monitor reinstatement activities after testing or repairs.

10) How can you identify an ISO (Isometric Drawing) in a P&ID (Piping and Instrumentation Diagram)?

An ISO in a P&ID can be identified by various elements such as:

Line number: The ISO will have a specific line number associated with it.
Service: The ISO may indicate the service or process that the line is carrying.
Instruments: The ISO may show instruments or equipment associated with the line.
Equipment: The ISO may represent equipment such as pumps, valves, or vessels.
Slope: The ISO may illustrate the direction or slope of the pipe.

11) What is an insulation kit?

An insulation kit is a set of materials used to provide insulation or electrical isolation between above-ground and underground components, typically in a piping system. It helps prevent corrosion, electrical conductivity, and heat transfer between different sections of the system.

12) What is an insulation gasket?

An insulation gasket is a type of gasket designed specifically for isolating or providing electrical insulation in flanged joints between dissimilar metals. It prevents galvanic corrosion and electrical current flow between the flanges, which can occur when two different metals are in contact. Insulation gaskets are commonly used in pipelines and other industrial applications. One example of an insulation gasket is the Pikotek gasket.

13) What are PIKOTEK Gaskets and what are their limitations?

PIKOTEK Gaskets are non-metallic gaskets that consist of a self-energized Teflon seal supported by a glass-reinforced epoxy laminated to a 316 stainless steel core. These gaskets offer certain advantages and limitations, which are as follows:

Advantages:

Non-metallic construction provides electrical insulation properties.
Self-energized Teflon seal enhances sealing performance.
The glass-reinforced epoxy provides structural support.
Suitable for various applications where non-metallic gaskets are required.

Limitations:

The minimum required gap between flanges when using PIKOTEK Gaskets is 3.2 mm.
They should not be used in services with temperatures of 154°C or higher.
They should not be used in hydrocarbon gas services where the flange rating is 300 or higher.
They should not be used when there is chemical incompatibility between the non-metallic components of the gasket and the service media.

14) What are the general points to be checked prior to a hydro test? (Pre-pressure checklist)

Before conducting a hydro test, it is important to perform a pre-pressure checklist to ensure proper preparation and adherence to safety and quality standards. The following are general points that should be checked:

Seal weld threaded nipples from headers to the first block of the valve (applicable for hydrocarbon service) as per SAES-L-110.
Verify that guides are in direct contact with the piping horizontal run at three locations with a minimum 6mm gap. Relocate guides as per the approved drawing. These guides should be welded to the pressure boundary.
Check the orientation of check valves to ensure the correct flow direction. Reverse the check valve if necessary and restore internals immediately after the test. Company representatives should witness this procedure.
Ensure that there is proper piping clearance to structural bracing, with a minimum spacing of 50mm.
Install permanent gaskets at flange sets 1, 4, 5, and 6 on ISO drawings as per approved torque tables. Install spectacle blinds in accordance with the approved P&ID.
Thoroughly remove all water and debris from low points/valve cavities, especially for in-line valves with SS 400 trim. Clean the cavities using dry compressed air and re-lubricate the sealing surfaces with an approved lubricant in preparation for the specified “ambient” lay-up mentioned in the test package.
Indicate “No Punch items” as applicable, ensuring that all necessary inspections and verifications have been completed.
The quality assurance (QA) team should review, initial, and date the pre-pressure checklist to certify its completeness. This helps ensure that all necessary steps have been taken before proceeding with the hydro test.

15) What is NCR, CAR, DR?

NCR (Non-Conformity Report): An NCR is a record that documents any deviation or non-conformance from the specified requirements. It identifies and reports the variation from the established standards, procedures, or specifications. The purpose of an NCR is to initiate corrective actions to address the non-conformity and prevent its recurrence in the future.

CAR (Corrective Action Report): A CAR is a record that outlines the actions taken to correct and eliminate the effects and causes of an existing non-conformity, defect, or other undesirable situation. It is generated in response to an NCR and includes a detailed plan for corrective measures to be implemented. The CAR aims to rectify the identified issues and prevent their reoccurrence through systematic investigation and action.

DR (Deviation Report): A DR is a record that documents the concessions granted by the client or owner to allow certain deviations from the project specifications. It is generated when a deviation from the specified requirements is necessary due to practical or technical reasons. The DR provides a formal authorization for the proposed deviation, outlining the justifications and any necessary conditions or limitations.

Aramco CBT Exam Questions for Welding QC Inspector