Practice Test For Los Angeles City Welder Certification Closed Book Section

The coating on an arc welding electrode acts as a scavenger by removing oxides and impurities. This is an important function because oxides and impurities can weaken the weld and affect its quality. By removing these substances, the coating helps to ensure a cleaner and stronger weld.

Arc strikes on the base metal should be avoided. Arc strikes can cause damage to the base metal, leading to weakened structural integrity and potential failure. This is especially critical in pressure pipe applications where any damage can compromise the safety and functionality of the system. Therefore, it is essential to prevent arc strikes from occurring in the first place to ensure the quality and reliability of the base metal.

Field welding should not be performed when the ambient temperature is lower than 0 degrees F because extremely cold temperatures can affect the quality and integrity of the weld. Cold temperatures can cause the metal to become brittle and increase the risk of cracking or failure. Therefore, it is important to avoid welding in such low temperatures to ensure the weld is strong and durable.

E71T-1 and E71T-2 electrodes both require shielding gas. Shielding gas is used in welding to protect the molten metal from atmospheric contamination, such as oxygen and nitrogen, which can cause defects in the weld. E71T-1 and E71T-2 electrodes are both classified as flux-cored arc welding (FCAW) electrodes, which means they have a flux-filled core that provides shielding to the weld. However, this flux alone is not sufficient to protect the weld from atmospheric contamination, so shielding gas is also required.

The "S" in ERXXS-X wire represents "Solid". This indicates that the wire is made of a single solid conductor, as opposed to being stranded or made of multiple smaller wires. Solid wires are typically used for applications that require a stable and consistent electrical connection, such as in residential and commercial wiring.

A bevel is not considered a joint because it is a type of cut or angle that is made on the edge of a material, rather than a connection between two separate pieces. A lap joint is formed when two pieces overlap each other, a corner joint is formed when two pieces meet at a 90-degree angle, and an edge joint is formed when two edges are joined together. However, a bevel is a slanted or angled cut that is made on the edge of a material for various purposes such as aesthetics or to create a smooth transition between two surfaces.

The Los Angeles City certified welding license needs to be renewed every 3 years. This means that after obtaining the license, the welder must go through a renewal process every 3 years to ensure that their skills and knowledge are up to date. This requirement helps to maintain the quality and safety standards in the welding industry and ensures that certified welders are continuously trained and assessed.

The welding symbol information referring to the arrow side of the joint is found below the reference line. This is because the reference line represents the joint, and the arrow side of the joint is the side where the weld is to be made. Therefore, any information related to the welding process, such as weld size, length, or specific instructions, is typically indicated below the reference line to clearly specify the requirements for that particular side of the joint.

The square wave refers to the shape of the output power. In welding, the output power is typically in the form of an electrical waveform. A square wave is a type of waveform that has a constant amplitude and alternates between two levels, typically high and low, in a square shape. This type of waveform is commonly used in certain welding processes, such as TIG (Tungsten Inert Gas) welding, where it helps to control the heat input and produce a stable arc.

The given description indicates the Visual Testing (VT) process. VT is a nondestructive examination method that involves inspecting the surface of a material or component to detect any visible discontinuities or defects. It is commonly used to verify fit-up, joint configuration, weld dimensions, and profiles. Unlike other NDE processes, such as PT (Penetrant Testing), RT (Radiographic Testing), and MT (Magnetic Particle Testing), VT specifically focuses on visual inspection.

The correct answer is contractor/fabricator. The prequalified Welding Procedure Specifications (WPS) are prepared by the contractor/fabricator. This means that the contractor or fabricator is responsible for developing and documenting the welding procedures that will be used for a specific project. This includes determining the appropriate welding techniques, materials, and parameters to ensure the quality and integrity of the welds. The contractor/fabricator plays a crucial role in ensuring that the welding procedures meet the required standards and specifications.

Low hydrogen electrodes are typically classified as E7018 or E7016. The last two digits of the electrode classification indicate the tensile strength of the weld metal in thousands of pounds per square inch (ksi). In this case, the correct answer is 5, 6, 8, which indicates that the weld metal has a tensile strength of 68 ksi.

The E6010 electrode is deep penetrating, meaning it can penetrate through thick materials effectively. It can be used in all positions, including overhead and vertical positions. However, it can only be used on Direct Current Reverse Polarity (DCRP) welding machines.

The minimum length of an intermittent fillet weld is 1 1/2". This means that the weld should be at least 1 1/2" long. The intermittent fillet weld is a type of weld that is not continuous and is made up of a series of smaller welds. It is commonly used when the joint does not require a continuous weld. The minimum length requirement ensures that the weld is strong enough to withstand the intended load and provides sufficient bonding between the two pieces being joined.

The correct answer is "100 KSI or less." This means that the D1.1 structural code covers applications that involve carbon and low alloyed steels with a minimum yield strength of 100 KSI or less.

A low hydrogen electrode may be rebaked once. This is typically done to remove any moisture or contaminants that may have been absorbed during storage. However, it is important to note that rebaking should only be done once, as repeated rebaking can negatively affect the performance and quality of the electrode.

Down hand welding refers to a welding technique where the weld is performed in a horizontal position, with the welder's hand moving downwards. This technique is commonly used for welding in the flat position, where the weld is performed on a horizontal surface. Therefore, the term "down hand welding" is synonymous with the flat position.

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7/16" - 1/16" = 6/16" reduce to lowest terms = 3/8"

The correct answer is 4. Fillet weld end return lengths have a maximum requirement of 4 times the nominal size of the weld. This means that the length of the return on the end of the fillet weld should be at least 4 times the size of the weld itself. This requirement ensures that the weld is strong and secure, providing sufficient reinforcement and preventing any potential failure or breakage.

When using the SMAW process, the electrode is positive only when using DCRP (Direct Current Reverse Polarity). In this polarity, the electrode is connected to the negative terminal of the power source, and the workpiece is connected to the positive terminal. This configuration allows for deeper penetration and better control over the weld pool. It is important to note that when using AC (Alternating Current), the polarity of the electrode constantly changes, and when using DCSP (Direct Current Straight Polarity), the electrode is connected to the positive terminal.

In GMAW (Gas Metal Arc Welding), the welding variable controlled by the wire feed speed is the current. The wire feed speed determines the rate at which the welding wire is fed into the weld pool. This, in turn, affects the amount of current flowing through the wire and ultimately determines the heat input and penetration of the weld. By adjusting the wire feed speed, the welder can control the current and, consequently, the quality and strength of the weld.

The legend for figures 3.2 & 3.3 does not cover preheat and interpass temperature. The legend typically provides information about the symbols or colors used in the figures to represent certain variables or conditions. In this case, the legend does not include any indication of how preheat and interpass temperature are represented in the figures. This means that the figures do not provide information about these important variables, which could be crucial for understanding the welding process being depicted.

A break in the arrow shaft of a weld symbol would have significance in a bevel or j-groove. This is because the arrow shaft represents the location and direction of the weld, and a break in the arrow shaft indicates that the weld is not continuous along the entire length of the joint. In a bevel or j-groove joint, a break in the arrow shaft would indicate that the weld does not extend to the root of the joint, which could affect the strength and integrity of the weld.

Welding out of position with an EXX2X rod can cause undercut. Undercut is a type of weld defect where the base metal along the edges of the weld joint is melted and removed, creating a groove or depression. This can weaken the weld and compromise its integrity. Welding out of position, such as welding vertically or overhead, increases the likelihood of undercut due to the gravitational pull on the molten metal. Using an improper welding rod, like the EXX2X rod mentioned, can also contribute to undercutting as it may not provide sufficient control over the weld pool.

The electrode classification EXXT-1 thru EXXT-6 requires to be run on DCEP (Direct Current Electrode Positive) polarity. DCEP polarity means that the electrode is connected to the positive terminal of the power source, while the workpiece is connected to the negative terminal. This polarity is commonly used for electrodes that have a heavy coating, such as EXXT-1 thru EXXT-6, as it helps to provide better arc stability and penetration.

The electrode used in the D1.1 practical exam is classified in F4 group.

The suffix numbers 1, 2, and 5 in FCAW electrodes indicate the need for shielding gas. This means that these specific electrodes require a shielding gas to protect the weld from atmospheric contamination and ensure proper weld quality.

An E7024 is considered to be in the F1 group.