A6 Flashcards
What does the term “fabrication” primarily refer to in piping systems?
A. Physical placement of subassemblies
B. Cutting, bending, forming, and welding of components
C. Final NDE and leak testing
D. Cleaning and flushing of piping systems
Cutting, bending, forming, and welding of components
Why are commercial pipe fabrication shops often preferred over site fabrication shops?
A. They are closer to installation sites
B. They employ more workers
C. They have specialized equipment and higher efficiency
D. They do not require heat treatment
They have specialized equipment and higher efficiency
For which pipe size is shop fabrication most commonly used in industrial applications?
A. NPS 1 (DN 25) C. NPS 2 ½ (DN 65) and larger
B. NPS 2 (DN 50) D. NPS 1 ½ (DN 40)
NPS 2 ½ (DN 65) and larger
What additional processes are included during the installation phase of piping systems?
A. Welding, final NDE, leak testing, and flushing
B. Cutting and forming of pipe components
C. Heat treatment and bending
D. Non-metallic pipe fabrication
Welding, final NDE, leak testing, and flushing
Why is it essential for fabrication and installation contractors to work closely with designers?
A. To reduce project costs
B. To ensure compliance with codes and address material limitations
C. To accelerate the installation timeline
D. To avoid the use of special alloys
To ensure compliance with codes and address material limitations
What must purchase specifications for piping materials and fabrication reflect to ensure proper practices are used?
A. The general recommendations of the applicable code
B. The specific requirements for material grade, product form, and heat treatment
C. The cost-saving practices recommended by the installer
D. Only the maximum allowable stress levels
The specific requirements for material grade, product form, and heat treatment
Which organization publishes Engineering Standards that provide guidance for many fabrication processes not covered by codes?
A. ASME
B. American Petroleum Institute (API)
C. Pipe Fabrication Institute (PFI)
D. Manufacturers Standardization Society (MSS)
Pipe Fabrication Institute (PFI)
Why heat treatment necessary after hot bending certain austenitic stainless steels?
A. To increase the material’s tensile strength
B. To improve weldability
C. To restore corrosion resistance lost during bending
D. To reduce the material’s thermal expansion coefficient
To restore corrosion resistance lost during bending
What is the primary purpose of installation drawings in piping systems?
A. To outline the materials required for pipe fabrication
B. To prepare detailed welding procedures
C. To specify plans, sections, and requirements for fabrication and installation
D. To determine the shipping requirements for pipe spools
To specify plans, sections, and requirements for fabrication and installation
What factors influence the division of a prefabricated piping system into subassemblies or spools?
A. Corrosion resistance and weldability of the materials
B. Dimensional and weight limitations for shipping and heat treatment
C. Field clearance requirements and valve tolerances
D. Sensitization range and allowable stress limits
Dimensional and weight limitations for shipping and heat treatment
What can “tolerance stack-up” in a piping system affect?
A. The weight distribution of the piping system
B. The overall dimensions of the system, especially in closely coupled systems
C. The weld quality of field joints
D. The selection of appropriate heat treatment methods
The overall dimensions of the system, especially in closely coupled systems
Why is oxyfuel gas cutting not effective for higher alloy materials?
A. It requires additional preheating
B. The cutting temperature is too low for these materials
C. The chemical reaction becomes inefficient with increasing alloy content
D. The process damages the material’s corrosion resistance
The chemical reaction becomes inefficient with increasing alloy content
Which process is commonly used for cutting higher alloy materials?
A. Oxyfuel gas cutting C. Mechanical cutting with saws
B. Plasma arc cutting D. Lapping and swaging
Plasma arc cutting
What is the main factor that might dictate the use of forming operations like bending and swaging in pipe fabrication?
A. The availability of welding fittings
B. The complexity of welding procedures
C. Economic considerations and special pipe sizes
D. The need for third-party inspection
Economic considerations and special pipe sizes
Which bending method is commonly used for coiling pipes and offers flexibility in choosing bending radii?
A. Compression bending C. Rotary draw bending
B. Ram bending D. Roll bending
Roll bending
Why is sand filling recommended for pipes with a diameter-to-thickness ratio of 10:1 or greater during hot bending?
A. To provide thermal insulation during heating
B. To reduce the chance of buckling by increasing rigidity
C. To achieve a smaller bending radius
D. To reduce the temperature required for bending
To reduce the chance of buckling by increasing rigidity
What is the key characteristic of the increment bending process?
A. It heats the entire pipe evenly throughout the process
B. It involves heating and bending in small sections sequentially
C. It is limited to pipes with a maximum diameter of NPS 10
D. It requires the use of roll bending machines
It involves heating and bending in small sections sequentially
What is the maximum wall thickness that can be bent using the induction bending process?
A. 2 inches (50 mm) C. 4 inches (100 mm)
B. 3 inches (75 mm) D. 5 inches (125 mm)
4 inches (100 mm)
Why is an internal mandrel often required when draw bending copper pipes?
A. To maintain the required bending temperature
B. To reduce the risk of buckling and ensure dimensional accuracy
C. To heat the pipe evenly during the process
D. To prevent thinning of the extrados
To reduce the risk of buckling and ensure dimensional accuracy
What forming operation involves reducing the size of pipe ends by forging, pressing, or rolling?
A. Extrusion C. Lapping
B. Swaging D. Heat treating
Swaging
What is essential to do before assembling piping subassemblies for welding?
A. Preheat the entire pipe to forging temperature
B. Clean weld surfaces of rust, scale, grease, and foreign substances
C. Perform a post-bending heat treatment
D. Increase the wall thickness of the pipe by 30%
Clean weld surfaces of rust, scale, grease, and foreign substances
What is the main advantage of Submerged Arc Welding (SAW)?
A. Ability to weld in all positions
B. Highest deposition rate among welding processes
C. Minimal interpass temperature control required
D. Effective for root pass welding without backing
Highest deposition rate among welding processes
Which welding process uses a non-consumable tungsten electrode and requires filler metal from an external source?
A. Shielded Metal Arc Welding (SMAW)
B. Submerged Arc Welding (SAW)
C. Gas Tungsten Arc Welding (GTAW)
D. Gas Metal Arc Welding (GMAW)
Gas Tungsten Arc Welding (GTAW)
Which welding process is considered most desirable for making root welds of the highest quality?
A. SMAW (Shielded Metal Arc Welding)
B. SAW (Submerged Arc Welding)
C. GTAW (Gas Tungsten Arc Welding)
D. FCAW (Flux Core Arc Welding)
GTAW (Gas Tungsten Arc Welding)
What position is referred to as the “1G position” in pipe welding?
A. Pipe vertical, weld horizontal.
B. Pipe inclined at 45°, fixed.
C. Pipe horizontal and rotated, weld in flat position.
D. Pipe horizontal and fixed, weld combination of positions.
Pipe horizontal and rotated, weld in flat position.
What shielding gases are typically used in GTAW (Gas Tungsten Arc Welding)?
A. Argon or helium. C. A mixture of argon and flux.
B. Carbon dioxide or oxygen. D. Nitrogen or hydrogen.
Argon or helium
What is the main purpose of preheating before welding ferritic materials?
A. To increase the cooling rate of the weld joint.
B. To reduce the formation of hydrogen-induced cracks.
C. To enhance the chemical composition of the base metal.
D. To ensure sigma phase formation during welding.
To reduce the formation of hydrogen-induced cracks.
What is the purpose of machine counterboring in piping fabrication?
A. To reduce the wall thickness of the pipe.
B. To ensure precise alignment of matching components.
C. To increase the heat resistance of the weld joint.
D. To eliminate the need for post-weld heat treatment.
To ensure precise alignment of matching components.
What is the recommended gap between the pipe and the socket for socket weld joints to allow for thermal expansion?
A. 1/8 in (3.0 mm) C. 1/4 in (6.0 mm)
B. 1/16 in (2.0 mm) D. No gap is required
1/16 in (2.0 mm)
For circumferential fillet welds between a pipe and a slip-on flange, what is the minimum weld leg size for the fillet between the hub and the pipe?
A. Equal to the pipe nominal wall thickness.
B. 1.09 times the pipe nominal wall or the thickness of the hub, whichever is smaller.
C. 1/16 in (2.0 mm) larger than the pipe nominal wall.
D. Equal to the flange’s inside diameter.
1.09 times the pipe nominal wall or the thickness of the hub, whichever is smaller.
Which type of steel is primarily used for service temperatures between 800°F and 1050°F (427°C to 565°C)?
A. Carbon steels C. Chromium molybdenum steels
B. Carbon molybdenum steels D. Stainless steels
Chromium molybdenum steels
What is the most common filler metal used for SMAW welding of carbon steel?
A. E-7018 C. E-7024
B. E-6010 D. E-8018
E-7018
What is the recommended filler material when welding copper to carbon steel?
A. Chromium-containing electrodes
B. Nickel filler after buttering the carbon steel with nickel
C. Silicon bronze or aluminum bronze electrodes without buttering
D. Copper-nickel alloys
Nickel filler after buttering the carbon steel with nickel
Why is welding of galvanized steel pipe not recommended?
A. It leads to incomplete weld penetration.
B. Toxic vapors are released during welding.
C. Galvanized coatings weaken the base metal.
D. The welds are incompatible with other coatings.
Toxic vapors are released during welding
Which filler metals are most often used for copper brazing?
A. Silver, copper-phosphorus, and copper-zinc.
B. Nickel, aluminum, and lead.
C. Tin, lead, and zinc.
D. Iron, chromium, and molybdenum.
Silver, copper-phosphorus, and copper-zinc.
Which type of solder is commonly used for most piping applications?
A. Tin-zinc solder C. Tin-lead solder
B. Tin-antimony solder D. Zinc-aluminum solder
Tin-lead solder
What is the purpose of annealing in ferritic steels?
A. To improve corrosion resistance
B. To reduce hardness and improve machinability
C. To increase residual stresses
D. To refine the grain structure
To reduce hardness and improve machinability
What heat treatment involves heating ferritic steel above the upper critical temperature, holding it, and then cooling it in still air?
A. Stress relieving C. Tempering
B. Normalizing D. Annealing
Normalizing
What is the main purpose of stress-relieving heat treatment in ferritic steels?
A. To harden the material
B. To reduce residual stresses from bending and welding
C. To increase impact resistance
D. To restore corrosion resistance
To reduce residual stresses from bending and welding
Which heat treatment method generates heat within the pipe wall using alternating current?
A. Resistance heating C. Induction heating
B. Torch heating D. Exothermic heating
Induction heating
What is the primary limitation of liquid penetrant examination?
A. It can only detect subsurface defects.
B. It requires a magnetic field for proper application.
C. It is suitable for surface defects only.
D. It cannot detect discontinuities in smooth surfaces.
It is suitable for surface defects only
Which nondestructive examination method requires the use of a magnetic field and iron powder to detect defects?
A. Radiographic examination C. Magnetic particle examination
B. Ultrasonic examination D. Liquid penetrant examination
Magnetic particle examination
What is the most effective method for removing tightly adhering scale and rust from ferritic steels?
A. Wire brushing
B. Grinding
C. Blasting with sand, shot, or grit
D. Degreasing with solvent
Blasting with sand, shot, or grit
What should be marked on valves and specialty items to ensure correctness during erection planning?
A. Material grade
B. Flow arrows and operational components
C. Pressure rating
D. Welding procedure qualifications
Flow arrows and operational components
What is a common practice when installing large, heavy piping subassemblies in power plants?
A. Fabricating all parts in the field
B. Erecting assemblies with the structure
C. Welding terminal points before subassembly erection
D. Using only temporary supports for final positioning
Erecting assemblies with the structure
Which welding processes are commonly used for field welding operations?
A. SMAW, GMAW, FCAW, and GTAW
B. Plasma cutting and oxyfuel gas cutting
C. Resistance welding and arc stud welding
D. Brazing and soldering
SMAW, GMAW, FCAW, and GTAW
What method is sometimes used for stress-relieving small pipe welds in the field?
A. Induction heating with automated temperature control
B. Torch heating with temperature-sensitive crayons
C. Full submersion in a controlled heat bath
D. Overbending and cooling without heat treatment
Torch heating with temperature-sensitive crayons
Which method is commonly used for surface examination in the field?
A. Magnetic particle inspection C. Liquid-penetrant methods
B. Ultrasonic testing D. Radiography using X-ray equipment
C. Liquid-penetrant methods
What should be done to ensure leak-tightness in threaded joints?
A. Avoid using any compounds or sealing methods
B. Use joint compounds compatible with the carried fluid
C. Tighten threads beyond recommended torque
D. Use only dryseal pipe threads
Use joint compounds compatible with the carried fluid
What is the recommended method for tightening bolts on flanged joints?
A. Tighten all bolts sequentially in a clockwise direction
B. Tighten bolts hand-tight and then use a torque wrench in a staggered sequence
C. Tighten bolts fully one at a time
D. Use lubricants and tighten bolts beyond their yield point
Tighten bolts hand-tight and then use a torque wrench in a staggered sequence
What type of joint is commonly used for buried cast-iron pipelines?
A. Compression-sleeve couplings C. Flanged joints
B. Bell and spigot joints D. Threaded joints
Bell and spigot joints
When should stops be removed from resilient and constant-effort supports during installation?
A. Before the line is welded and insulated
B. After the line is completely welded, tested, and insulated
C. During the hydrostatic leak test
D. Before the system reaches its “hot” position
After the line is completely welded, tested, and insulated
What is the most common method of leak testing for piping systems?
A. Pneumatic testing C. Ultrasonic leak detection
B. Hydrostatic testing D. Radiographic examination
Hydrostatic testing
Why is it important to have a relief valve during leak testing?
A. To provide a backup pressure gauge
B. To prevent excessive overpressure due to possible thermal expansion of the test fluid
C. To ensure the test fluid flows through the entire system
D. To manage any leaks that occur during the test
To prevent excessive overpressure due to possible thermal expansion of the test fluid
What is a key consideration when conducting a leak test with respect to the system’s yield strength?
A. The system should not exceed 100% of its yield strength during the test
B. The system should not exceed 90% of its yield strength during the test
C. The test pressure should always be kept at the design pressure
D. The system should be pressurized to twice the design pressure
The system should not exceed 90% of its yield strength during the test
What is recommended before conducting a leak test to ensure safety?
A. Perform a visual inspection of all welded joints only
B. Prepare a written procedure outlining the scope and boundaries of the test
C. Reduce the pressure to 50% of the design pressure to prevent damage
D. Only test the piping without considering the rest of the system
Prepare a written procedure outlining the scope and boundaries of the test
