Aramco Piping QC Inspector Exam

This article is about Aramco Piping QC Inspector Exam for all QC Inspectors and engineers. This questions are prepared based on Aramco PID Format of CBT test and general questions asked from qc and engineers professionals.

How do you identify fittings and flanges?

To identify fittings and flanges, the following characteristics are typically considered:

Material Classification: Fittings and flanges are identified based on the material they are made of, such as carbon steel, stainless steel, or a specific alloy.
Size: The size of fittings and flanges is indicated by the nominal pipe size (NPS) or the actual dimensions, such as diameter or length.
Rating: Flanges are assigned a pressure rating, which indicates their ability to withstand certain operating pressures. Common rating systems include Class, PN (Pressure Number), or pressure in pounds per square inch (PSI).
Joint Type: Fittings and flanges can have different joint types, such as lap joint, socket weld, threaded, or butt weld. The joint type determines how the fitting or flange connects to the piping system.
Face: Flanges have specific face types, such as raised face (RF) or flat face (FF), which determine the sealing surface for gaskets.

How do you check piping for the correct schedule?

To check piping for the correct schedule, the following methods can be employed:

Verify Pipe Material Thickness: The material thickness of the pipe can be measured using a Vernier caliper or ultrasonic thickness (UT) testing. This ensures that the actual thickness corresponds to the specified schedule.
Stenciling by the Manufacturer: The pipe may have stenciling or markings applied by the manufacturer, indicating the schedule or wall thickness. These markings can be visually checked against the required schedule.
Heat Number and Traceability: The pipe should have a heat number assigned by the manufacturer, which allows for traceability of the material. The heat number can be cross-referenced with the Material Test Certificate (MTC) provided by the manufacturer to ensure compliance with the specified schedule.

What is the standard mill tolerance for piping 2’’ & less?

The standard mill tolerance for piping 2” and less is typically 12% of the nominal wall thickness. This means that the actual wall thickness of the pipe can deviate by up to 12% from the specified nominal wall thickness. It is important for piping inspectors to take this tolerance into account when verifying the wall thickness of the pipe during inspections.

What is the tolerance for ovality of piping?

The tolerance for ovality of piping is specified in SAES-L-350, paragraph 9.2. According to this standard, the maximum allowable ovality is 5% of the nominal diameter at any cross section of the pipe, except for the weld end. At the weld end, the maximum allowable ovality is reduced to 3% of the nominal diameter. This means that the pipe’s cross-sectional shape should not deviate more than these specified percentages from a perfect circle. Piping inspectors should measure and verify the ovality of the pipe to ensure it meets these tolerance requirements.

What is the difference between torquing CS and SS bolting?

CS:- Yield strength High; Torque value High

SS:- Yield strength low; Torque value low

The difference between torqueing carbon steel (CS) and stainless steel (SS) bolting lies in the yield strength and torque values.

Yield Strength: Carbon Steel (CS): CS materials generally have a higher yield strength compared to stainless steel. This means that CS bolts can withstand higher levels of stress before permanent deformation or failure occurs. Stainless Steel (SS): SS materials typically have a lower yield strength compared to carbon steel, making them less resistant to deformation under stress.
Torque Value: Carbon Steel (CS): Due to its higher yield strength, CS bolts require higher torque values to achieve the desired clamping force. This is necessary to ensure proper joint integrity and prevent leakage. Stainless Steel (SS): SS bolts, with their lower yield strength, require lower torque values to achieve the same clamping force as CS bolts. Excessive torque on SS bolts can lead to overloading and potential damage to the fastener or the joint.

What are jackscrews and when are they required?

Jackscrews are devices used in flange joint assemblies to facilitate the separation and opening of the joint for maintenance purposes. They are typically required when the flange joint assembly includes components that may need frequent separation, such as orifice plates, spectacle plates, spacers, screens, and drop-out spools.

The jackscrews allow for easier disassembly of the flange joint by providing a means to apply force and create separation between the flanges. This enables access to the components within the joint for inspection, replacement, or maintenance activities.

When jackscrews are used, they should be installed in a manner that allows accessibility from both sides of the pipe. In the case of orifice flanges, jackscrews are specifically required to be installed at the 3 o’clock and 9 o’clock positions, as specified in SAES-L-310, paragraph 17.7.

It is important to follow the relevant standards and guidelines, such as SAES-L-310, to ensure the proper installation and use of jackscrews in flange joint assemblies, promoting efficient maintenance and ensuring the integrity of the joint.

What is often overlooked during orifice flange fabrication?

During orifice flange fabrication, there are several important factors that are often overlooked. These include:

Grinding and machining of welded joints: The inside surface of the welded joints at orifice flanges should be ground and machined smooth. This is specified in SAES-L-350, paragraph 10.4.2. This step is crucial to ensure proper flow and accuracy in the measurement of the fluid passing through the orifice.
Orientation of taps: The orientation of taps in orifice flanges should be in accordance with SAES-J-0001. Proper alignment and positioning of the taps are necessary to ensure accurate measurement and optimal performance of the orifice.
Spacing between flanges: Parallel pipe lines with adjacent orifice fittings should have a minimum spacing of 300 mm (12 inches) between the outside diameters of the flanges. This spacing is required when horizontal taps are used. If this spacing is not practical, the guidelines specified in SAES-J-0001 should be followed.
Staggering of orifice flanges: Orifice flanges in adjacent lines should be staggered to ensure proper spacing. No two pairs of orifice flanges should be less than 1 m (3 ft) apart. This arrangement helps to avoid interference and maintain the accuracy of the flow measurement.

What is the maximum diameter piping allowed in hazardous service?

In hazardous service, the maximum allowable diameter for piping depends on the joint type. According to SAES-L-110, the maximum diameter allowed for hazardous service is as follows:

Socket Weld:

2 inches for maintenance and minor modification of existing piping systems.
1-½ inches for new construction.

Threaded:

1-½ inches for standard fittings and valves.
2 inches maximum when required for maintenance or minor field modification of existing piping systems.

These limitations on maximum diameter help ensure the safety and integrity of the piping system in hazardous service. It’s important to adhere to these guidelines to maintain the appropriate level of reliability and risk management in such environments.

What is the minimum sized piping that can be installed on pipe racks?

The minimum sized piping that can be installed on pipe racks is typically 1 inch in diameter (Ø1″). This is a common minimum size requirement for piping mounted on pipe racks. It’s important to note that specific project requirements and standards may vary, so it’s always recommended to refer to the applicable codes, standards, and project specifications for accurate and up-to-date information regarding minimum piping sizes on pipe racks.

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Aramco Piping QC Inspector Exam