Certified Pipefitter Journeyman Exam — Questions and Answers

Question 1: On an orthographic piping drawing, what does a circle with a horizontal line through the center, drawn on a pipe, typically indicate?

A union fitting (Correct answer)
A spectacle blind in the open position
A pipe cap
A pipe nipple close

Correct answer: A union fitting

A circle bisected by the pipe centerline is the standard symbol for a union, indicating a mechanical joint that allows the pipe to be disconnected without cutting.

Question 2: A concentric reducer connects an 8-inch pipe (OD = 8.625 in) to a 6-inch pipe (OD = 6.625 in). If the centerline of the larger pipe is at elevation 102.50 feet, at what elevation is the centerline of the smaller pipe at the outlet of the reducer?

102.00 feet
101.50 feet
102.50 feet (Correct answer)
103.00 feet

Correct answer: 102.50 feet

A concentric reducer keeps both pipe centerlines on the same axis — the centerlines are co-linear. Therefore, the centerline elevation does not change from inlet to outlet; it remains at 102.50 feet. An eccentric reducer (flat on bottom or top) would shift the centerline. Many pipefitters confuse concentric and eccentric reducers in elevation calculations.

Question 3: A Class 600 globe valve is being replaced in-kind in a high-pressure steam line. The old valve used a flexible graphite spiral-wound gasket with an inner ring. The new valve body has a raised-face flange. The available gasket stock includes: (1) full-face spiral-wound graphite, (2) spiral-wound graphite with inner and outer rings (double-ring), and (3) ring-type spiral-wound graphite without outer ring. Which gasket is CORRECT for this application and why?

The spiral-wound graphite with inner and outer rings (double-ring), because the outer ring acts as a compression stop preventing over-compression of the winding, which is critical at Class 600 bolt loads (Correct answer)
Any of the three are acceptable; ASME B16.20 permits all spiral-wound types on raised-face flanges at Class 600
The full-face spiral-wound graphite, because the full face distributes bolt load evenly across the entire flange face
The ring-type spiral-wound graphite without outer ring, because the raised face flange already acts as a compression stop

Correct answer: The spiral-wound graphite with inner and outer rings (double-ring), because the outer ring acts as a compression stop preventing over-compression of the winding, which is critical at Class 600 bolt loads

On raised-face flanges, ASME B16.20 recommends spiral-wound gaskets with both an inner ring (which prevents the winding from collapsing into the bore under high bolt loads) and an outer ring (which serves as a compression limiter, preventing the spiral winding from being over-compressed). At Class 600 bolt loads, without the outer ring, the winding can be crushed beyond its designed seating stress, causing extrusion and potential leakage. The full-face design is reserved for flat-face flanges such as cast iron. The double-ring design is the ASME-recommended standard for raised-face steel flanges.

Question 4: The flow velocity in a 3-inch pipe (ID = 3.068 in) is 8 ft/s. If the pipe transitions to a 6-inch pipe (ID = 6.065 in), what is the approximate velocity in the larger pipe?

6.0 ft/s
4.0 ft/s
2.0 ft/s (Correct answer)
1.0 ft/s

Correct answer: 2.0 ft/s

Using continuity (A₁V₁ = A₂V₂): area ratio ≈ (3.068/6.065)² ≈ 0.256, so V₂ ≈ 8 × 0.256 ≈ 2.05 ft/s.

Question 5: A pipefitter is performing a hot tap on a 10-inch high-pressure natural gas main at 250 psig. The procedure requires a shell cutter with a pilot drill. At what point in the sequence is the highest risk of an uncontrolled blowout, and what control prevents it?

When pressure-testing the hot-tap fitting before drilling; controlled by maintaining test pressure below 50% of the main's MAOP
When tightening the packing gland on the hot-tap machine; controlled by using a torque wrench calibrated to the manufacturer's specification
When the pilot drill first breaches the pipe wall; controlled by ensuring the hot-tap machine's gate valve is in the fully open position before drilling
When retracting the cutter assembly after the coupon is cut; controlled by closing the isolation valve on the hot-tap fitting before retracting the cutter (Correct answer)

Correct answer: When retracting the cutter assembly after the coupon is cut; controlled by closing the isolation valve on the hot-tap fitting before retracting the cutter

After the cutter completes its cut, the coupon is still held on the pilot drill inside the pressurized zone. Retracting the assembly without first closing the isolation valve on the hot-tap fitting would expose the full pipe pressure directly to the atmosphere through the hot-tap machine's packing, causing an uncontrolled blowout. The correct sequence is: complete the cut, close the isolation valve, then retract the cutter assembly safely behind the closed valve. The gate valve being open during drilling is correct procedure (not a risk point), and pressure testing is a pre-drill safety step, not the highest-risk moment.

Question 6: When performing a socket weld on a 2-inch Schedule 80 carbon steel pipe, what is the correct gap that must be maintained between the pipe end and the bottom of the socket before welding?

1/16 inch (1.6 mm) (Correct answer)
No gap is required — the pipe must bottom out in the socket
3/16 inch (4.8 mm)
1/8 inch (3.2 mm)

Correct answer: 1/16 inch (1.6 mm)

ASME B31.3 and B16.11 require a 1/16-inch (1.6 mm) gap between the pipe end and the socket bottom before welding. This gap allows for thermal expansion during welding and in service, preventing stress concentration and potential cracking at the root of the weld. Bottoming out the pipe eliminates this expansion space and can cause joint failure.

Question 7: A pump requires that its suction line be a minimum 5 pipe diameters of straight pipe before the suction flange. The pump has a 4-inch suction nozzle (4" NPS, OD = 4.500"). What is the minimum straight pipe length required?

20 inches of straight pipe
18 inches of straight pipe
22.5 inches of straight pipe (Correct answer)
4.5 inches of straight pipe

Correct answer: 22.5 inches of straight pipe

Minimum straight pipe = 5 × OD = 5 × 4.500" = 22.5 inches.

Question 8: A pipefitter calculates that 3 inches of pipe is needed per degree of bend on a 2-inch pipe. How long a pipe section is needed to fabricate a 30° bend?

60 inches
45 inches
90 inches (Correct answer)
30 inches

Correct answer: 90 inches

Required length = 3 inches/degree × 30 degrees = 90 inches of pipe.

Question 9: Which of the following joining methods is most suitable for connecting small-bore (≤ 2 inches) carbon steel piping in a high-pressure hydraulic system where frequent disassembly is NOT required?

Socket weld (Correct answer)
Grooved joint
Flanged joint
Threaded joint

Correct answer: Socket weld

Socket welds are strong, high-integrity joints ideal for small-bore, high-pressure applications like steam or hydraulic lines where a permanent connection is desired. Threaded joints are typically for lower pressures, flanged joints are used for larger pipes or where disassembly is needed, and grooved joints are for moderate pressure and systems requiring some flexibility.

Question 10: During hot-work on a high-pressure steam line, a pipefitter notices the line isolation valve — a gate valve — shows zero pressure on the downstream gauge but the valve stem packing is visibly weeping steam. What is the correct interpretation and immediate action?

The zero reading confirms isolation; the weeping packing is a separate maintenance item
Open the isolation valve fully to relieve any trapped pressure before reseating it
The downstream gauge may be faulty; verify isolation integrity by cracking a drain valve downstream before proceeding (Correct answer)
Packing weepage is cosmetic; apply extra packing gland torque and continue the hot work

Correct answer: The downstream gauge may be faulty; verify isolation integrity by cracking a drain valve downstream before proceeding

A zero downstream gauge reading alone does not confirm positive isolation — the gauge itself may be defective, blocked, or sensing a dead leg. Weeping stem packing indicates live pressure is reaching the valve body, which is a warning sign of possible seat leakage through. The correct procedure is to crack a downstream drain or vent to positively verify no flow before trusting the gauge, consistent with double-block-and-bleed isolation principles.

Question 11: A pipefitter is joining two dissimilar metals: a P-No. 1 carbon steel pipe to a P-No. 8 austenitic stainless steel pipe. Which filler metal classification is most appropriate for this weld per ASME Section IX guidelines?

ER70S-6
ER316L
ER308L
ER309L (Correct answer)

Correct answer: ER309L

ER309L is specifically designed for welding dissimilar metals, particularly carbon steel to austenitic stainless steel. Its higher chromium and nickel content compared to ER308L provides a dilution buffer against the carbon steel's composition. ER308L is used for 304 SS to 304 SS, ER316L for 316 SS to 316 SS, and ER70S-6 is a carbon steel filler inappropriate for stainless applications.

Question 12: During radiographic testing (RT) of a socket weld joint, the radiograph reveals a dark circular image in the center of the weld area. The inspector must differentiate between a void (porosity) and a burn-through. Which characteristic on the radiograph BEST distinguishes burn-through from porosity?

Burn-through produces a lighter image than the surrounding weld metal due to increased metal thickness in that area
Porosity indications are elongated while burn-through indications are perfectly circular
Porosity appears as multiple scattered indications while burn-through always appears as a single isolated dark spot
Burn-through produces a sharper, well-defined dark circle with higher density contrast at its edges compared to the diffuse gradient of a gas pore (Correct answer)

Correct answer: Burn-through produces a sharper, well-defined dark circle with higher density contrast at its edges compared to the diffuse gradient of a gas pore

On a radiograph, burn-through produces a distinctly sharper-edged, higher-density (darker) circular image because the weld has actually collapsed or melted through, creating a true hole or severe depression with abrupt thickness change at the margins — resulting in a steep density gradient at the edges. Gas porosity, by contrast, is a void within solid metal and appears with a softer, more gradual density gradient at its boundaries because the surrounding weld metal tapers around the pore. Both can appear as single spots, both can appear circular, and both produce dark images (thinner material = more radiation passes through). Edge sharpness and density gradient are the key differentiators.

Question 13: Which of the following welding defects is characterized by the weld metal failing to fuse completely with the base metal or an adjoining weld bead, creating a potential failure point along the weld toe or between passes?

Undercut
Slag Inclusion
Lack of Fusion (Correct answer)
Porosity

Correct answer: Lack of Fusion

Lack of Fusion is a weld discontinuity where the molten weld metal does not properly fuse with the base material or a previous weld bead. This creates a gap or seam that acts as a stress concentrator, severely weakening the joint. It can be caused by improper travel speed, incorrect amperage, or poor joint preparation.

Question 14: When calculating the load on each leg of a two-leg bridle sling, what is the effect of decreasing the sling angle (angle between the sling leg and horizontal)?

Decreasing the angle has no effect on leg tension
Decreasing the angle only affects the horizontal force, not the vertical
Decreasing the angle reduces the load per leg
Decreasing the angle increases the load per leg, requiring a higher rated sling (Correct answer)

Correct answer: Decreasing the angle increases the load per leg, requiring a higher rated sling

As the bridle sling angle from horizontal decreases (sling legs become more horizontal), the tension in each sling leg increases significantly. At 30 degrees from horizontal, each leg carries twice the load it would at 90 degrees (straight up).

Question 15: A pipefitter is installing a carbon steel line carrying wet hydrogen sulfide (H₂S) service at 450 psi. Which pipe specification is most appropriate to prevent sulfide stress cracking (SSC)?

ASTM A53 Grade B ERW pipe heat-treated to a tensile strength above 90 ksi
ASTM A106 Grade C seamless pipe for its higher yield strength
ASTM A106 Grade B seamless pipe with a maximum hardness of 22 HRC (Correct answer)
ASTM A335 P11 alloy pipe normalized and tempered

Correct answer: ASTM A106 Grade B seamless pipe with a maximum hardness of 22 HRC

NACE MR0175/ISO 15156 requires carbon steel in wet H₂S service to have a maximum hardness of 22 HRC (237 HBW) to resist sulfide stress cracking. A106 Grade B seamless pipe meeting this hardness limit is the correct choice. A53 ERW pipe is generally excluded from sour service due to weld seam susceptibility, and higher-strength materials (Grade C) actually increase SSC risk because harder steels are more susceptible to hydrogen embrittlement.

Question 16: Which career path would best suit a pipefitter who excels at reading technical drawings and coordinating multi-trade work?

Procurement warehouse manager
Industrial hygienist
Safety data sheet (SDS) auditor
Piping design coordinator or BIM (Building Information Modeling) coordinator (Correct answer)

Correct answer: Piping design coordinator or BIM (Building Information Modeling) coordinator

BIM coordinators use their field knowledge to manage digital models and resolve conflicts between trades before construction begins.

Question 17: A reducing tee is used in a piping system to:

Change flow direction 90 degrees on the main run
Branch off a smaller pipe from a larger main line (Correct answer)
Reduce pressure in a straight run
Join two pipes of equal size at an angle

Correct answer: Branch off a smaller pipe from a larger main line

A reducing tee has a branch outlet smaller than the main run, allowing a smaller pipe to tap into a larger header.

Question 18: Which type of fire extinguisher should be used on a Class C (energized electrical) fire?

Water extinguisher
Class A dry chemical only
Class K extinguisher
CO2 extinguisher (Correct answer)

Correct answer: CO2 extinguisher

CO2 extinguishers are appropriate for Class C (electrical) fires because they are non-conductive and leave no residue.

Question 19: A 150-foot carbon steel steam line is installed at 70°F and operates at 650°F. Using a coefficient of thermal expansion of 6.5 × 10⁻⁶ in/in/°F, what is the total linear expansion of the pipe?

8.45 inches
7.54 inches
5.22 inches
6.79 inches (Correct answer)

Correct answer: 6.79 inches

The formula is ΔL = L × α × ΔT, where L must be in inches. Convert: 150 ft × 12 = 1,800 inches. ΔT = 650 − 70 = 580°F. Then: 1,800 × 6.5 × 10⁻⁶ × 580 = 6.786 inches ≈ 6.79 inches. A common error is using 150 (feet) instead of 1,800 (inches) as L, which yields only 0.566 inches — far too low. Another trap is using the wrong ΔT by forgetting to subtract the installation temperature.

Question 20: When a pipefitter notices a co-worker not using required PPE, what is the correct first action?

Stop work and inform the co-worker and supervisor (Correct answer)
Immediately report to OSHA
Ignore it and continue working
Document it in the incident log at end of shift

Correct answer: Stop work and inform the co-worker and supervisor

The correct action is to stop work, inform the co-worker of the hazard, and notify the supervisor to ensure compliance and prevent injury.

Question 21: When reading a piping orthographic drawing, you encounter a weld symbol with a melt-through symbol (a filled circle) on the opposite side of the reference line from the weld symbol. What does this combination specifically require?

An additional fillet weld applied to the reverse side of the joint
A backing ring to be used on the root pass of the weld
Complete joint penetration with the root surface flush on the back side
A full penetration weld visible and inspectable from both sides of the joint (Correct answer)

Correct answer: A full penetration weld visible and inspectable from both sides of the joint

The melt-through symbol (solid filled circle) placed on the opposite side of the reference line from the groove weld symbol indicates that complete joint penetration must be achieved and the weld must be visible and inspectable from both sides — essentially a full penetration weld verified on the back face. This differs from a backing symbol (rectangle) and does not mandate a fillet on the reverse side or require a backing ring.

Question 22: What does ASME B31.3 require for a 'Category D' fluid service piping system regarding leak testing?

Full radiographic examination on all welds
Hydrostatic test at 1.5 times design pressure
No testing required — visual inspection only
Initial service leak test (system may be inspected during first pressurization to operating conditions) (Correct answer)

Correct answer: Initial service leak test (system may be inspected during first pressurization to operating conditions)

ASME B31.3 Category D fluid service (non-flammable, non-toxic fluid at design pressure 150 psi or less and temperature between -20 and 366 degrees F) permits an initial service leak test rather than requiring a pre-service hydrostatic test.

Question 23: When welding in the 6G position, what does the '6' indicate?

6-inch pipe diameter
Inclined fixed pipe (45 degrees from horizontal) (Correct answer)
Vertical fixed pipe
Horizontal fixed pipe

Correct answer: Inclined fixed pipe (45 degrees from horizontal)

The 6G position is a fixed-pipe position with the pipe axis inclined at 45 degrees from horizontal. It is considered the most challenging qualification position because the welder must continuously change technique as they weld around the pipe.

Question 24: Using the pipe weight formula W = 10.68 × t × (OD − t), what is the total weight of a 30-foot section of 6-inch Schedule 80 carbon steel pipe? (OD = 6.625 inches, wall thickness t = 0.432 inches)

714.3 lb
857.1 lb (Correct answer)
917.1 lb
771.2 lb

Correct answer: 857.1 lb

Weight per foot = 10.68 × 0.432 × (6.625 − 0.432) = 10.68 × 0.432 × 6.193 = 28.57 lb/ft. Total weight = 28.57 × 30 = 857.1 lb. Choice A (714.3 lb) results from multiplying 28.57 by 25 feet instead of 30. Choice B (771.2 lb) comes from using an incorrect wall thickness. Choice D (917.1 lb) is the classic trap: omitting the wall-thickness subtraction and computing 10.68 × 0.432 × 6.625 × 30 — treating the pipe as if the full OD were solid metal.

Question 25: A pipefitter is performing an orbital GTAW weld on a 3-inch sanitary (hygienic) stainless steel tube for a pharmaceutical process line requiring full internal purging. The internal bead exhibits consistent brown and blue oxide discoloration ('sugar') along the entire weld length. Which corrective action should be taken FIRST?

Switch from 100% argon to a 98% argon/2% hydrogen forming gas for the purge
Increase weld travel speed to reduce heat input and oxide formation
Increase the internal purge gas flow rate to at least 20 CFH
Verify that the purge gas dew point is below −40°F (−40°C) and check all fittings and backing dams for leaks (Correct answer)

Correct answer: Verify that the purge gas dew point is below −40°F (−40°C) and check all fittings and backing dams for leaks

Brown and blue oxide on the internal bead indicates oxygen contamination of the purge atmosphere — the weld pool was exposed to oxygen levels far above the acceptable threshold (typically <50 ppm for pharmaceutical-grade welds per ASME BPE). The first corrective action is to verify dew point of the purge gas and inspect for leaks at purge dams, fittings, and connections, since even a small leak can introduce enough oxygen to cause heavy oxidation despite adequate flow rate. Simply increasing flow rate will not help if contaminated atmospheric air is entering through a leak. Hydrogen forming gas is effective but addresses an already-correct setup, and changing travel speed does not address the root cause of oxygen ingress.

Question 26: During a critical lift plan review, the load's center of gravity is determined to be 60% of the total length from the left pick point. The load weighs 24,000 lbs and is being lifted with two vertical rigging points. What load does the RIGHT pick point carry?

12,000 lbs
14,400 lbs
16,000 lbs
9,600 lbs (Correct answer)

Correct answer: 9,600 lbs

When the center of gravity is offset, loads distribute inversely proportional to the distance from each pick point. The CG is 60% from the left, meaning it is 40% from the right. The right pick point carries the portion of load proportional to how far the CG is from the LEFT point: Right load = 24,000 × 0.40 = 9,600 lbs. The left pick point carries 24,000 × 0.60 = 14,400 lbs. This inverse relationship is a common source of error in rigging calculations.

Question 27: A piping plan drawing shows a line with alternating long and short dashes. This typically represents:

A buried or underground pipe (Correct answer)
A future pipeline
A steam tracing line
A high-pressure line

Correct answer: A buried or underground pipe

A hidden or buried pipe is conventionally shown with a long-short dashed line pattern on plan drawings.

Question 28: What does the acronym 'SDS' stand for in a workplace safety context?

Safe Drilling Standards
Safety Data Sheet (Correct answer)
Structural Durability Score
Standard Design Specification

Correct answer: Safety Data Sheet

SDS stands for Safety Data Sheet, which replaced MSDS under OSHA's Hazard Communication Standard (HazCom 2012).

Question 29: What does LOTO stand for in industrial safety, and which OSHA standard governs it for general industry?

Lock-On/Tag-Out; OSHA 29 CFR 1910.120 — HAZMAT Operations
Lockout/Tagout; OSHA 29 CFR 1910.132 — PPE Requirements
Lockout/Tagout; OSHA 29 CFR 1910.147 — Control of Hazardous Energy (Correct answer)
Lockout/Tagout; OSHA 29 CFR 1926.147 — Construction Electrical Safety

Correct answer: Lockout/Tagout; OSHA 29 CFR 1910.147 — Control of Hazardous Energy

LOTO (Lockout/Tagout) is the control of hazardous energy, governed by OSHA 29 CFR 1910.147 for general industry.

Question 30: A project's Welding Procedure Specification (WPS) provides detailed instructions for a specific weld. Which of the following is NOT typically considered an 'essential variable' that would require the WPS to be re-qualified if changed?

The brand of the welding machine used, assuming it meets power requirements. (Correct answer)
A change in the welding process (e.g., from SMAW to GTAW).
A change in the F-Number of the filler metal.
A significant change in the base material group (e.g., from carbon steel to stainless steel).

Correct answer: The brand of the welding machine used, assuming it meets power requirements.

A Welding Procedure Specification (WPS) is qualified based on essential variables that affect the mechanical properties of the weld. Changes to the base metal P-Number, welding process, filler metal F-Number, or removal of post-weld heat treatment are essential variables requiring re-qualification. The specific brand of the welding machine is generally a non-essential variable, provided it can deliver the specified electrical characteristics (amperage, voltage) detailed in the WPS.

Question 31: A signal person needs to communicate 'Raise the Boom and Lower the Load' to a crane operator. According to standard ANSI/OSHA hand signals, what is the correct signal?

Arm extended vertically, index finger pointing up, making small circles.
Arm extended horizontally, thumb pointing up, flexing fingers in and out. (Correct answer)
Both arms extended horizontally, palms down, swinging back and forth.
Arm extended horizontally, thumb pointing down, flexing fingers in and out.

Correct answer: Arm extended horizontally, thumb pointing up, flexing fingers in and out.

The standard OSHA and ANSI hand signal for 'Raise the Boom and Lower the Load' is to extend the arm horizontally with the thumb pointing up, then opening and closing the fingers until the action is complete.

Question 32: A pipefitter must join a carbon steel pipe to a 304L stainless steel pipe using SMAW. Which filler metal selection and technique combination is most appropriate?

E7018 electrode with preheat to 300°F on the stainless side
E309L electrode with a butter layer on the carbon steel side first (Correct answer)
E308L electrode applied directly across the dissimilar joint
E316L electrode with PWHT at 1100°F applied to the full joint

Correct answer: E309L electrode with a butter layer on the carbon steel side first

Dissimilar metal welds between carbon steel and austenitic stainless steel require an austenitic filler with sufficient alloy content to dilute carbon steel pickup and resist sensitization. E309L is specifically designed for this application. The 'buttering' technique — depositing a layer of E309L on the carbon steel side first, then filling the joint — further controls dilution and reduces the risk of carbon migration into the stainless heat-affected zone. E308L has insufficient alloy reserves to compensate for carbon steel dilution. E7018 is a carbon steel electrode inappropriate for stainless. PWHT at 1100°F on austenitic stainless would cause sensitization.

Question 33: A vertical steam pipe (riser) must be supported at each floor level it passes through. Which type of support is specifically designed to clamp onto the pipe and transfer the pipe's dead weight to the building's structure at that elevation?

Pipe Saddle
Riser Clamp (Correct answer)
Clevis Hanger
Roller Support

Correct answer: Riser Clamp

A Riser Clamp is specifically designed for supporting vertical runs of pipe. It clamps tightly around the pipe, and the clamp itself rests on the floor or structural steel, thereby transferring the weight of the pipe section to the structure.

Question 34: What does the abbreviation 'BOP' mean on a piping isometric drawing?

Bore of pipe
Bottom of pipe (Correct answer)
Beginning of project
Back of pipe

Correct answer: Bottom of pipe

BOP stands for Bottom of Pipe and indicates the elevation measurement is taken from the bottom of the pipe.

Question 35: A pipefitter is reviewing the Safety Data Sheet (SDS) for a solvent used to clean pipe threads. In which section of the SDS would the pipefitter find the most detailed information about the required Personal Protective Equipment (PPE)?

Section 11: Toxicological Information
Section 4: First-Aid Measures
Section 8: Exposure Controls/Personal Protection (Correct answer)
Section 2: Hazard(s) Identification

Correct answer: Section 8: Exposure Controls/Personal Protection

According to the OSHA Hazard Communication Standard's 16-section format for SDSs, Section 8, titled 'Exposure Controls/Personal Protection,' provides specific recommendations for minimizing worker exposure. This includes requirements for Personal Protective Equipment (PPE) such as specific types of gloves, eye protection, and respiratory protection needed for safe handling.

Question 36: A pipefitter needs to calculate the pipe length needed for a rolling offset. The horizontal offset (set) is 8 inches, the vertical offset (rise) is 6 inches, and the advance (run) is 18 inches. What is the true pipe length?

24.08 inches
22.36 inches
20.59 inches (Correct answer)
18.97 inches

Correct answer: 20.59 inches

Step 1: Find the diagonal of the two offsets — √(8²+6²) = √(64+36) = √100 = 10 inches. Step 2: Apply Pythagorean theorem with the advance — true length = √(10²+18²) = √(100+324) = √424 ≈ 20.59 inches. This two-step Pythagorean process is mandatory for rolling offsets and is frequently confused with a simple single-step calculation.

Question 37: What is meant by 'back-purging' during stainless steel pipe welding?

Cleaning the weld joint with back-hand motion
Using back-pressure to prevent weld burn-through
Reversing the welding direction to fill undercut
Flowing inert gas inside the pipe to protect the weld root from oxidation (Correct answer)

Correct answer: Flowing inert gas inside the pipe to protect the weld root from oxidation

Back-purging means flowing argon or nitrogen through the inside of the pipe to displace oxygen and protect the weld root from oxidation (sugaring).

Question 38: What does Schedule 80 indicate on a pipe specification?

The pipe's outside diameter
The wall thickness of the pipe (Correct answer)
The maximum operating pressure
The pipe material grade

Correct answer: The wall thickness of the pipe

Schedule 80 refers to the wall thickness of the pipe — higher schedule numbers indicate thicker walls.

Question 39: What is the approximate weight of water in a 12-inch NPS Schedule 40 pipe that is 20 feet long? (12" Sch 40: ID = 11.938", weight of water ≈ 0.0361 lb/in³)

250 lbs
720 lbs
350 lbs
484 lbs (Correct answer)

Correct answer: 484 lbs

Volume = π/4 × ID² × length = 0.7854 × 11.938² × 240" = 26,740 in³. Weight = 26,740 × 0.0361 = ~965 lbs.

Question 40: A constant-effort (constant support) hanger is used when:

The pipe has no thermal movement
The pipe load must remain constant throughout vertical thermal movement (Correct answer)
The pipe must be isolated from vibration
The pipe requires rigid anchoring at that point

Correct answer: The pipe load must remain constant throughout vertical thermal movement

Constant-effort hangers maintain a constant load on the pipe regardless of vertical displacement caused by thermal expansion or contraction.

Question 41: A piping plan drawing at elevation +28'-6" shows a 4" line with the notation 'BOP EL. +27'-0"'. The pipe is shown with standard wall Schedule 40 carbon steel. What does this notation establish, and what is the centerline elevation of this pipe?

BOP means Bottom of Pipe; since Schedule 40 4" pipe has a wall thickness of 0.237", the centerline is at 27'-0" minus 0.237" = 26'-11¾"
BOP means Bottom of Pipe and establishes that the pipe invert (inside bottom) is at 27'-0"; for gravity flow design, no centerline calculation is needed
BOP means Bottom of Pipe; the pipe's bottom outside surface is at elevation 27'-0". For 4" Sch 40 pipe (OD = 4.500"), the centerline is at 27'-0" + 2.250" = 27'-2¼" (Correct answer)
BOP means Base of Pipe Support; elevation 27'-0" refers to the top of the structural steel support, and centerline must be calculated separately from hanger data

Correct answer: BOP means Bottom of Pipe; the pipe's bottom outside surface is at elevation 27'-0". For 4" Sch 40 pipe (OD = 4.500"), the centerline is at 27'-0" + 2.250" = 27'-2¼"

BOP = Bottom of Pipe, and the elevation given (27'-0") refers to the bottom of the pipe's outer surface (outside diameter), not the invert or pipe support. For 4" NPS Schedule 40 carbon steel pipe, the nominal OD is 4.500" per ASME B36.10. The pipe radius is 4.500" ÷ 2 = 2.250" = 2¼". Therefore, centerline elevation = 27'-0" + 2¼" = 27'-2¼". This distinction (BOP vs. CL vs. TOP vs. invert) is critical for pipefitters calculating support heights, clash detection, and field measurement. Note that wall thickness is irrelevant to this calculation — BOP is referenced to the OD, not the bore.

Question 42: What additional certification can a highly skilled pipefitter pursue to advance into pipe stress analysis or design engineering?

NCCER Level 4 Advanced Pipefitter Module
ASME Certified Piping Inspector (API 570) or professional engineering licensure after meeting education and experience requirements (Correct answer)
OSHA 30-hour general industry certification
AWS Certified Welder qualification

Correct answer: ASME Certified Piping Inspector (API 570) or professional engineering licensure after meeting education and experience requirements

API 570 Piping Inspector certification or a professional engineering license allows pipefitters with additional education to move into inspection or engineering roles.

Question 43: When specifying a variable spring hanger for a high-temperature steam line, the 'cold load' and 'hot load' differ. Which condition governs the hanger rod and structural attachment sizing?

The hot load, because it represents operating conditions
The cold load, because thermal expansion has not yet occurred
The greater of the two loads, regardless of which condition produces it (Correct answer)
The average of the cold and hot load values

Correct answer: The greater of the two loads, regardless of which condition produces it

Hanger rods, structural attachments, and building steel must be sized for the greater of the cold or hot load. Although variable spring hangers are designed to accommodate both conditions, the maximum load — which may occur in either the installed (cold) or operating (hot) position — determines the structural capacity required. Designing only for hot load can leave the structure undersized during hydrostatic testing or cold startups.

Question 44: A pipefitter is preparing to perform a pneumatic pressure test (using nitrogen) on a new process line because the system cannot support the weight of water. The design pressure is 300 psig. Per ASME B31.3, to what initial pressure must the system be brought and held for leak checking BEFORE incrementally raising to full test pressure?

10% of the test pressure
50% of the design pressure (150 psig)
The full test pressure applied in a single step for pneumatic systems
25 psig — the initial check pressure regardless of design pressure (Correct answer)

Correct answer: 25 psig — the initial check pressure regardless of design pressure

ASME B31.3 paragraph 345.5.4 requires that for pneumatic tests, pressure be raised to the lesser of one-half the test pressure or 25 psig — and held while a preliminary leak check is performed using leak detection fluid. This is because pneumatic testing stores far more energy than hydrostatic testing and catastrophic failure during a pneumatic test is extremely violent. The 25 psig ceiling for the initial step exists specifically to limit stored energy during the initial leak inspection regardless of design pressure.

Question 45: A pipefitter is assigned to a nuclear power plant's safety-related piping system classified as ASME Class 1. Which design code governs the fabrication and installation of this piping, and what distinguishes it from all other industrial piping codes?

ASME B31.3 Process Piping Category M fluid service — it prohibits threaded joints entirely
ASME Section VIII Division 2 — it uses allowable stress values at 2/3 of ultimate tensile strength
ASME Section III, Division 1, Subsection NB — it requires design by analysis rather than design by rule, and mandates 100% volumetric examination of all pressure-retaining welds (Correct answer)
ASME B31.1 Power Piping — it requires 100% radiographic examination of all welds

Correct answer: ASME Section III, Division 1, Subsection NB — it requires design by analysis rather than design by rule, and mandates 100% volumetric examination of all pressure-retaining welds

ASME Section III, Division 1, Subsection NB governs Class 1 nuclear piping. Unlike B31.1 or B31.3 which use 'design by rule' with tabulated allowables, Section III NB requires fatigue analysis and design by analysis. It also mandates 100% volumetric (RT or UT) examination of all pressure-retaining welds — a requirement not found in any other standard piping code. This reflects the zero-leak tolerance in safety-related nuclear systems.

Question 46: Under ASME B31.3 Process Piping Code, which of the following piping systems is classified as Category M fluid service, triggering the most stringent fabrication and examination requirements?

A steam piping system operating above 750°F and 1500 psig
A piping system carrying anhydrous hydrogen fluoride (HF) at any pressure (Correct answer)
A cryogenic nitrogen system operating below -100°F
A high-pressure hydraulic system operating above 2500 psig

Correct answer: A piping system carrying anhydrous hydrogen fluoride (HF) at any pressure

ASME B31.3 defines Category M fluid service as service where the potential for personnel exposure is considered significant and a single exposure to a very small quantity of toxic fluid — caused by leakage — can produce serious irreversible harm to persons on breathing or bodily contact. Anhydrous HF fits this definition precisely due to its extreme toxicity at very low concentrations. High-temperature steam, high-pressure hydraulics, and cryogenic nitrogen are hazardous but fall under normal or high-pressure fluid service classifications, not Category M.

Question 47: On an isometric piping drawing, how is a field weld (FW) distinguished from a shop weld?

Field welds are shown as dashed weld symbols; shop welds are solid
Field welds are shown as filled (black) circles; shop welds are open circles
Field welds are shown as open circles; shop welds are filled (black) circles (Correct answer)
There is no distinction on the drawing

Correct answer: Field welds are shown as open circles; shop welds are filled (black) circles

By standard convention, field welds are represented as open circles at the weld point on isometric drawings, while shop (fabrication) welds are filled black circles, making it easy to plan prefabrication vs. field installation work.

Question 48: A senior pipefitter is evaluating whether to pursue the ASNT Level II certification in Radiographic Testing (RT) as a career growth tool. Which assessment most accurately characterizes the strategic value of this credential within a pipefitting career path?

Obtaining RT Level II automatically qualifies the pipefitter for ASME-authorized inspection work under the NB-23 National Board Inspection Code
ASNT Level II supersedes the need for a Certified Welding Inspector credential and covers equivalent scope
RT Level II is primarily valuable only in nuclear power plant environments and has negligible value in oil and gas pipefitting
RT Level II significantly increases marketability for QC inspector and owner's representative roles, but pursuing it without also understanding ASME Section V and Section IX creates a credential gap that knowledgeable employers will identify during technical interviews (Correct answer)

Correct answer: RT Level II significantly increases marketability for QC inspector and owner's representative roles, but pursuing it without also understanding ASME Section V and Section IX creates a credential gap that knowledgeable employers will identify during technical interviews

ASNT RT Level II opens QC and inspection career paths that command premium pay and are highly sought in oil, gas, petrochemical, and power generation. However, employers in these sectors routinely ask RT Level II candidates about ASME Section V (NDE methods) and Section IX (welding qualifications) because RT is commonly used to verify weld integrity. A candidate who holds the ASNT credential but cannot speak to the code framework it operates within will be filtered out in technical interviews for senior inspection roles. Pairing RT with code literacy is essential.

Question 49: In GTAW (TIG) pipe welding, the high-frequency arc start is preferred over scratch start primarily because:

It eliminates the need for shielding gas
It produces higher amperage output
It increases travel speed
It prevents tungsten contamination of the weld pool (Correct answer)

Correct answer: It prevents tungsten contamination of the weld pool

High-frequency arc starting allows the arc to initiate without touching the tungsten to the base metal, preventing tungsten inclusions in the weld and preserving electrode geometry.

Question 50: During a multi-leg rigging lift with asymmetric loading, a journeyman proposes using a screw-pin anchor shackle and mousing (wire-tying) the pin to prevent it from backing out. A master pipefitter rejects this and substitutes a bolt-type (round pin with nut and cotter pin) shackle instead. What is the primary technical reason for this substitution?

Screw-pin shackles are not rated for use with wire rope slings, only with chain slings
Mousing a screw-pin shackle is prohibited by OSHA on any overhead lift
Bolt-type shackles have a higher working load limit than equivalently sized screw-pin shackles
Under dynamic or side loading in multi-leg rigging, the pin is subject to rotational forces that mousing wire cannot reliably resist; a bolt-type shackle's mechanical nut-and-cotter-pin design positively locks the pin regardless of rotation (Correct answer)

Correct answer: Under dynamic or side loading in multi-leg rigging, the pin is subject to rotational forces that mousing wire cannot reliably resist; a bolt-type shackle's mechanical nut-and-cotter-pin design positively locks the pin regardless of rotation

In multi-leg rigging, asymmetric loads cause the shackle body to rotate relative to the sling. This rotational force acts directly on a screw pin in the unscrewing direction. Mousing with soft wire is only a secondary precaution and can fail under repeated or shock loading — it is not a positive mechanical lock. A bolt-type shackle's pin is secured by a nut threaded fully on and locked with a cotter pin, providing a mechanically positive retention that cannot be defeated by pin rotation. Industry rigging standards (ASME B30.26) recommend bolt-type shackles for any application with rotation, side loading, or sustained overhead use.

Question 51: What is the internal cross-sectional area of a 6-inch nominal pipe with an inside diameter of 6.065 inches?

32.45 sq in
26.67 sq in
36.00 sq in
28.89 sq in (Correct answer)

Correct answer: 28.89 sq in

Area = π × r² = 3.1416 × (3.0325)² ≈ 28.89 square inches.

Question 52: A pipefitter working in a refinery is tasked with installing a bypass spool on an active 10-inch steam header operating at 600 psi and 750°F. The work requires use of a live-tap hot tapping procedure. Which condition would AUTOMATICALLY disqualify this line from hot tapping without exception?

The steam header is classified as a Category M fluid service under ASME B31.3 (Correct answer)
The hot tap machine's pilot drill diameter exceeds 60% of the pipe's inner diameter
The ambient temperature at the work site is below 40°F
The line has a nominal wall thickness below the minimum calculated for the operating pressure

Correct answer: The steam header is classified as a Category M fluid service under ASME B31.3

ASME B31.3 Category M fluid service designates systems where a single failure could cause irreversible harm to personnel — including certain high-pressure steam systems at elevated temperatures. Hot tapping on Category M systems is prohibited without exception because the risk of an uncontrolled release during drilling cannot be adequately mitigated. Wall thickness below minimum (option A) is a disqualifying condition but can theoretically be addressed by reinforcing fittings; cold ambient temps (option B) affect procedure but don't automatically disqualify; pilot drill sizing (option D) is a procedural concern, not an absolute disqualifier.

Question 53: When performing a branch connection weld on a 12-inch run pipe using the set-on (o-let) method, an MT (magnetic particle) examination reveals a linear indication running longitudinally along the toe of the branch fillet weld, oriented parallel to the weld axis. Under ASME B31.3 Normal Fluid Service acceptance criteria, how must this indication be evaluated?

The indication is acceptable if it is less than 3/16 inch in length and not connected to the weld root
The indication is acceptable provided the weld passes a subsequent hydrostatic pressure test at 1.5× design pressure
Linear indications of any length are rejectable regardless of orientation when detected at the weld toe by MT (Correct answer)
Linear indications parallel to the weld axis are considered non-relevant and require no disposition

Correct answer: Linear indications of any length are rejectable regardless of orientation when detected at the weld toe by MT

ASME B31.3 Table 341.3.2 specifies that for magnetic particle examination of welds, all linear indications are rejectable — there is no minimum acceptable length for linear indications detected in welds (unlike PT/MT criteria for base metal). A linear indication at the weld toe is particularly concerning because the toe is a stress concentration zone prone to fatigue cracking. The orientation parallel to the weld axis does not make it 'non-relevant'; non-relevance applies only to indications caused by geometry (e.g., sharp corners, threads) that are verified to be false indications.

Question 54: In a closed-loop hydronic heating system, what is the role of the expansion tank?

To increase system pressure during peak demand
To store excess water for makeup
To separate air from the water loop
To accommodate volume changes as water expands and contracts with temperature (Correct answer)

Correct answer: To accommodate volume changes as water expands and contracts with temperature

The expansion tank provides a cushion to absorb the increased water volume as it heats up, preventing dangerous pressure buildup in the closed system.

Question 55: When using an oxyacetylene torch for pipe brazing, the correct flame adjustment for most copper alloy work is:

Neutral flame (Correct answer)
Carburizing flame
Reducing flame
Oxidizing flame

Correct answer: Neutral flame

A neutral flame (balanced oxygen and acetylene) is correct for brazing copper alloys as it neither adds carbon nor oxidizes the base metal.

Question 56: Under OSHA's Process Safety Management (PSM) standard (29 CFR 1910.119), what is the primary purpose of a Process Hazard Analysis (PHA)?

To analyze the efficiency of process operations for cost reduction
To establish the testing schedule for pressure relief devices
To identify, evaluate, and control hazards associated with processes that involve highly hazardous chemicals (Correct answer)
To document the chemical properties of all materials used in the plant

Correct answer: To identify, evaluate, and control hazards associated with processes that involve highly hazardous chemicals

A PHA systematically identifies and evaluates potential hazards in a process, allowing controls to be implemented before incidents occur.

Question 57: On a blueprint, a symbol for a pipe fitting shows a circle with a dot in the center, connecting two perpendicular lines. This represents which type of fitting view?

A 90-degree elbow shown from the side
A tee fitting with the branch flowing towards the viewer (Correct answer)
A flanged joint
A concentric reducer

Correct answer: A tee fitting with the branch flowing towards the viewer

This symbol represents a tee fitting where the main pipe runs horizontally and the branch is directed straight out, towards the person viewing the drawing. The circle represents the end view of the branch pipe, and the dot signifies its center.

Question 58: What is a 'weldolet,' and when is it the preferred branch connection method over a standard tee fitting?

A weldolet replaces a flange when bolted connections are not permitted
A weldolet is used only on plastic or fiberglass pipe systems
A weldolet is a branch fitting that butt-welds to the header pipe and the branch pipe; preferred when the branch is significantly smaller than the header, no tee fitting is available for the header size, or when reinforced branch connections are required by code (Correct answer)
A weldolet is a threaded branch fitting for use in low-pressure service

Correct answer: A weldolet is a branch fitting that butt-welds to the header pipe and the branch pipe; preferred when the branch is significantly smaller than the header, no tee fitting is available for the header size, or when reinforced branch connections are required by code

A weldolet is an integrally-reinforced butt-welding branch fitting (per MSS SP-97) that is contour-cut and welded to the OD of the header pipe; preferred when branch-to-run ratios require reinforcement, when header sizes exceed available tee fittings, or when full-penetration welds are required by specification.

Question 59: A wire rope sling has a Diameter-to-Sheave (D/d) ratio of 10:1 during a lift. Compared to a D/d ratio of 25:1, what approximate reduction in sling efficiency must the rigger account for?

Approximately 35% reduction in working load limit
Approximately 18% reduction in working load limit (Correct answer)
No reduction — D/d ratio only matters for wire rope drums
Approximately 7% reduction in breaking strength

Correct answer: Approximately 18% reduction in working load limit

Wire rope bending over sheaves or hooks causes loss of efficiency due to internal wire stress. At a D/d ratio of 25:1 (sheave diameter to rope diameter), efficiency is approximately 95–97%. At a D/d of 10:1, efficiency drops to approximately 79–82%. This represents roughly an 18% reduction in effective WLL that the rigger must factor into the rigging plan. ASME B30.9 and manufacturer data confirm these efficiency curves. Ignoring bend radius when specifying slings for tight radii is a common field error leading to premature rope fatigue or sudden failure.

Question 60: A pipefitter is joining a carbon steel pipe to a stainless steel pipe. Which filler metal is typically used for this dissimilar metal weld?

ER309L (Correct answer)
ER70S-6
ER308L
ER316L

Correct answer: ER309L

ER309L is the standard filler metal for dissimilar metal welds between carbon steel and stainless steel because its higher alloy content accommodates dilution from both base metals.

Question 61: Which ASME standard governs the dimensions of factory-made butt-welding fittings such as elbows, tees, and reducers?

ASME B16.11
ASME B16.9 (Correct answer)
ASME B31.3
ASME B16.5

Correct answer: ASME B16.9

ASME B16.9 covers factory-made wrought steel butt-welding fittings, specifying dimensions, tolerances, and pressure-temperature ratings for elbows, tees, reducers, and caps.

Question 62: What is the primary purpose of a check valve in a piping system?

To allow manual shutoff
To control pressure
To regulate flow rate
To prevent backflow (Correct answer)

Correct answer: To prevent backflow

Check valves allow flow in one direction only and automatically prevent reverse flow (backflow) in the system.

Question 63: When fabricating a lateral (Y-branch) fitting, the branch pipe intersects the header at an angle typically less than 90 degrees. What is the most critical layout challenge?

Determining the pipe insulation thickness
Selecting the correct pipe schedule
Choosing the correct flange rating
Developing the accurate compound saddle cut profile on both the header and branch pipe (Correct answer)

Correct answer: Developing the accurate compound saddle cut profile on both the header and branch pipe

The compound saddle cut must accurately match the curvature of the header on the branch pipe end so the joint fits tightly with minimal gap before welding.

Question 64: A pipefitter is installing a relief valve on a steam system where the system MAWP is 250 psig. The relief valve set pressure is 250 psig. Per ASME Section VIII and applicable piping codes, what is the maximum allowable inlet pressure drop (in % of set pressure) between the protected vessel and the relief valve inlet under flowing conditions?

15%
10%
5% (Correct answer)
3%

Correct answer: 5%

ASME Section VIII Div. 1, UG-135(b) and API RP 520 Part II specify that the pressure drop in the inlet piping to a pressure relief valve shall not exceed 3% of the relief valve set pressure under rated flow conditions for spring-loaded valves — this prevents chatter. However, for the total inlet pressure drop including all fittings and the block valve (if any), ASME B31.1 and most jurisdictional interpretations adopt 3% as the limit. Wait — API 520 Part II Section 5.6.1 specifically states the inlet pressure loss shall not exceed 3% of the set pressure. The 3% rule is the widely cited threshold. Answer A (5%) is incorrect per API 520. The correct answer is 3% (Answer B). Correction: the correct answer is 3%, which corresponds to correctIndex 1.

Question 65: If a pipe run must drop 6 inches over a horizontal distance of 10 feet to achieve proper drainage slope, what is the slope expressed as a fraction per foot?

1 inch per foot
3/4 inch per foot
1/2 inch per foot (Correct answer)
1/4 inch per foot

Correct answer: 1/2 inch per foot

6 inches ÷ 10 feet = 0.6 inches/foot. Expressed as a fraction, this rounds to approximately 1/2 inch per foot (0.5"/ft).

Question 66: What is the developed length of a 90° long-radius elbow fitting for a 3-inch NPS pipe?

7.07 inches (Correct answer)
4.50 inches
14.14 inches
9.42 inches

Correct answer: 7.07 inches

Developed length of a 90° LR elbow = (π/2) × CLR = 1.5708 × (1.5 × NPS) = 1.5708 × 4.5 = 7.07 inches.

Question 67: Which of the following drawing types is NOT drawn to scale but provides a three-dimensional representation of a single pipeline, showing all fittings, dimensions, and elevations?

Piping Isometric Drawing (Correct answer)
Plot Plan
Orthographic Drawing
Piping and Instrumentation Diagram (P&ID)

Correct answer: Piping Isometric Drawing

Piping isometric drawings are unique in that they show a single pipe run in a 3D view. They are not drawn to scale; instead, dimensions are written directly on the drawing to ensure accuracy for fabrication and installation.

Question 68: What is a 'hot pass' in pipe welding, and why is it performed immediately after the root pass?

A pass made with high amperage to increase deposition rate
A purge gas verification pass before welding
A weave bead applied to the cap pass for cosmetic finish
A pass made while the root pass is still warm to burn out any trapped slag and ensure fusion into the root (Correct answer)

Correct answer: A pass made while the root pass is still warm to burn out any trapped slag and ensure fusion into the root

The hot pass is deposited shortly after the root pass, while the weld is still warm, to burn out any residual slag, bridge porosity, and ensure full fusion to the root bead, which is critical for pressure piping.

Question 69: What does the abbreviation 'BOP' stand for on piping drawings?

Base of Piping
Bottom of Platform
Bottom of Pipe (Correct answer)
Back of Pipe

Correct answer: Bottom of Pipe

BOP stands for Bottom of Pipe and is used to indicate elevations measured from the lowest point of the pipe exterior.

Question 70: When making a socket weld connection, AWS D10.11 recommends that the pipe be inserted into the fitting and then pulled back approximately:

1/16 inch before welding (Correct answer)
Flush with the bottom of the socket
1/2 inch before welding
1/4 inch before welding

Correct answer: 1/16 inch before welding

Pulling the pipe back 1/16 inch from the socket bottom allows for thermal expansion during welding and prevents crevice corrosion from a zero-gap fit.

Question 71: What is the minimum preheat temperature typically required for P91 chrome-moly alloy steel pipe welding?

400°F (204°C) (Correct answer)
600°F (315°C)
100°F (38°C)
300°F (149°C)

Correct answer: 400°F (204°C)

P91 (9Cr-1Mo) alloy steel requires a minimum preheat of 400°F (204°C) to prevent hydrogen-induced cracking and ensure proper martensitic transformation.

Question 72: On a P&ID, what does a dashed line connecting an instrument to a control valve typically represent?

A pneumatic signal line (Correct answer)
A process connection
An electrical signal line
A capillary tube connection

Correct answer: A pneumatic signal line

On standard P&IDs following ISA 5.1, a dashed line between an instrument and a control element represents a pneumatic (air pressure) signal, while solid lines represent process connections and dotted lines represent electrical signals.

Question 73: Pipe shoes (pipe saddles) are used on insulated lines primarily to:

Reduce water hammer effects in the line
Attach the pipe permanently to structural steel
Transfer load to the support steel without compressing or damaging the insulation (Correct answer)
Increase friction between pipe and support

Correct answer: Transfer load to the support steel without compressing or damaging the insulation

Pipe shoes extend below the insulation to rest on the support, keeping the insulation intact and continuous.

Question 74: During hot-work operations near a process line containing residual hydrogen sulfide (H₂S), air monitoring shows 8 ppm at the work area boundary. Under OSHA 29 CFR 1910.1000, which statement is MOST accurate regarding permissible exposure limits (PEL) and required controls?

8 ppm is below the IDLH of 50 ppm; air-purifying respirators are acceptable and hot-work may continue without a permit
8 ppm exceeds the OSHA PEL ceiling of 1 ppm; work must stop and the area evacuated until concentrations drop below the ceiling
8 ppm is below the H₂S PEL of 20 ppm ceiling; no respiratory protection is required but continuous monitoring must continue (Correct answer)
8 ppm is within the OSHA action level; supplied-air respirators are mandatory but work may proceed

Correct answer: 8 ppm is below the H₂S PEL of 20 ppm ceiling; no respiratory protection is required but continuous monitoring must continue

OSHA 29 CFR 1910.1000 Table Z-2 establishes H₂S at a ceiling of 20 ppm (acceptable maximum peak 50 ppm for 10 minutes if no other measurable exposure occurs). At 8 ppm the ceiling PEL is not exceeded. However, continuous monitoring is still mandated given the dynamic nature of H₂S release. The IDLH is 50 ppm; supplied-air respirators are required only at or above the ceiling. Air-purifying respirators are NOT approved for H₂S in confined or enclosed environments regardless of concentration.

Question 75: What is the purpose of a pressure relief valve (PRV) in a piping system, and what code governs its sizing for pressure vessels?

It prevents backflow; sized per ANSI/ISA standards
It maintains constant system pressure; sized per ASME B31.3
It acts as a flow control device; sized per the fluid's specific gravity
It protects equipment and piping from overpressure by opening to discharge excess pressure; vessels sized per ASME Section VIII, process relief per API 520/521 (Correct answer)

Correct answer: It protects equipment and piping from overpressure by opening to discharge excess pressure; vessels sized per ASME Section VIII, process relief per API 520/521

A pressure relief valve (PRV) is a safety device that automatically opens when system pressure exceeds the set pressure, discharging fluid to protect the piping and equipment from overpressure failure. For pressure vessels, sizing is governed by ASME Section VIII; API 520/521 cover process relief system design.

Question 76: A pipefitter is tasked with lifting an L-shaped pipe spool. To ensure a level and stable lift, the single lifting point must be positioned directly above the spool's:

Longest leg
Geometric center
Center of gravity (Correct answer)
Heaviest component

Correct answer: Center of gravity

For a load to be lifted without tilting or tumbling, the main hook or lifting point must be directly above the load's center of gravity. The center of gravity is the balance point of the object, where the entire weight can be considered to be concentrated.

Question 77: When using a chain hoist to lift a pipe section near electrical lines, the minimum safe approach distance for unqualified workers near 50 kV lines is:

5 feet
15 feet
3 feet
10 feet (Correct answer)

Correct answer: 10 feet

OSHA 29 CFR 1926.1408 requires unqualified workers to maintain at least 10 feet of clearance from power lines up to 50 kV.

Question 78: What is the primary purpose of a weld coupon bend test in ASME Section IX welder qualification?

Measure the weld bead width and reinforcement
Measure the weld's tensile strength only
Test the weld for pressure tightness
Evaluate weld ductility and detect surface and subsurface discontinuities in the weld and HAZ (Correct answer)

Correct answer: Evaluate weld ductility and detect surface and subsurface discontinuities in the weld and HAZ

The guided bend test evaluates weld ductility and reveals discontinuities (cracks, porosity, lack of fusion, incomplete penetration) in the weld and heat-affected zone that might not be visible on the surface.

Question 79: A pipefitter needs to enter a permit-required confined space, such as a large vessel, to perform a modification. Which of the following roles is required to be stationed outside the space for the entire duration of the entry?

The Competent Person
The Rescue Team Captain
The Attendant (Correct answer)
The Project Supervisor

Correct answer: The Attendant

OSHA's standard for Permit-Required Confined Spaces (29 CFR 1910.146) mandates that a trained individual, known as the Attendant, be stationed outside the space while an authorized entrant is inside. The attendant's duties include monitoring the entrant, being aware of potential hazards, and summoning rescue services if needed, but they may not enter the space themselves.

Question 80: When cutting and threading stainless steel pipe for a chemical process system, which practice is the certified pipefitter responsible for that differs most critically from working with carbon steel?

Increasing the thread engagement length by one full thread to compensate for stainless steel's lower shear strength
Deburring the pipe ID with a stainless steel brush before threading to prevent weld slag inclusions
Using dedicated cutting and threading tools that have never contacted carbon steel, to prevent iron particle contamination that can initiate corrosion in the stainless steel (Correct answer)
Applying cutting oil rated for stainless steel at a higher volume than used for carbon steel

Correct answer: Using dedicated cutting and threading tools that have never contacted carbon steel, to prevent iron particle contamination that can initiate corrosion in the stainless steel

Cross-contamination of stainless steel with carbon steel particles is a critical concern because embedded iron particles will corrode rapidly and can initiate pitting corrosion on the stainless surface, compromising corrosion resistance. Certified pipefitters working on stainless systems are responsible for maintaining segregated tools — dedicated vises, pipe cutters, dies, and wire brushes — that have never been used on carbon steel. While correct cutting fluids and deburring are also good practices, tool segregation is the most critical differentiator specific to stainless work.

Question 81: A piping and instrumentation diagram (P&ID) shows a control valve symbol with a diagonally hatched body and the letter 'FO' next to it. What does this designation mean for system shutdown behavior?

The valve requires manual override on loss of instrument air or power
The valve fails open on loss of instrument air or power (Correct answer)
The valve fails closed on loss of instrument air or power
The valve holds its last position on loss of instrument air or power

Correct answer: The valve fails open on loss of instrument air or power

'FO' on a P&ID control valve designation stands for 'Fail Open,' meaning that upon loss of the actuating signal (instrument air or electrical power), the valve spring-returns to the fully open position. This is a critical process safety designation — pipefitters must install the correct actuator spring orientation to achieve the intended fail-safe state. 'FC' denotes Fail Closed and 'FL' or 'FI' denotes Fail-in-Last-position.

Question 82: A pipefitter fabricates a 3-piece mitered 90° elbow. At what angle from square must each end piece be cut?

15.0°
22.5° (Correct answer)
45.0°
30.0°

Correct answer: 22.5°

A 3-piece miter assembly contains 2 miter joints (not 3). The total 90° turn is distributed equally across those 2 joints: 90° ÷ 2 = 45° per joint. Because each joint is formed by two mating pipe ends, each individual cut is half the joint angle: 45° ÷ 2 = 22.5° from square. Choice D (45°) is the per-joint turn angle before halving for the two-sided cut. Choice C (30°) is the error of dividing by the number of pieces (90° ÷ 3) rather than the number of joints. Choice A (15°) has no geometric basis in standard miter fabrication.

Question 83: When using a magnetic particle inspection (MPI) method on a carbon steel weld, a linear indication is detected running parallel to the weld axis at the toe of the weld. This type of indication is MOST consistent with which defect?

Undercutting at the weld toe caused by excessive heat input (Correct answer)
Lamellar tearing in the heat-affected zone of the base metal
Crater cracking at the weld termination point
Lack of fusion along the weld groove face

Correct answer: Undercutting at the weld toe caused by excessive heat input

A linear MPI indication running parallel to the weld axis specifically at the toe of the weld is the classic signature of undercutting. Undercutting creates a groove at the weld toe where the base metal was melted away and not filled, producing a notch that acts as a stress concentrator. MPI detects the sharp discontinuity at this groove as a sharp linear indication precisely parallel to and at the edge of the weld bead. Lack of fusion appears along the fusion line (below surface, better detected by UT); crater cracking appears at weld endpoints and is transverse or star-shaped; lamellar tearing appears as step-like subsurface cracks in rolled plate.

Question 84: According to ANSI/ASME B31.3, what is the minimum required pneumatic leak test pressure for process piping?

1.1 times design pressure (Correct answer)
1.5 times design pressure
2.0 times design pressure
1.25 times design pressure

Correct answer: 1.1 times design pressure

ANSI/ASME B31.3 specifies that pneumatic leak testing must be performed at a minimum of 1.1 times the design pressure.

Question 85: A 6-inch Schedule 40 pipe makes a 45° offset using two 45° elbows. The travel distance between elbow centerlines is 36 inches. What is the true offset (rise) distance?

22.63 inches
50.91 inches
30.00 inches
25.46 inches (Correct answer)

Correct answer: 25.46 inches

For a 45° offset, the true offset = travel × 0.7071 (the sine of 45°). So 36 × 0.7071 = 25.46 inches. The travel is the hypotenuse of the right triangle formed; multiplying by sin(45°) gives the rise (offset). A common mistake is multiplying by the cosine or confusing travel with run.

Question 86: A rigger must select a shackle for a straight vertical lift of 8,500 lbs. The rigging involves a 45° included angle between two sling legs meeting at the shackle pin. What is the minimum Working Load Limit (WLL) the shackle must be rated for?

12,020 lbs
6,010 lbs
4,785 lbs
8,500 lbs (Correct answer)

Correct answer: 8,500 lbs

The shackle at the top of the rig (at the crane hook or master link) carries the entire load regardless of the sling angle below it. The two sling legs create increased tension within each leg due to the 45° included angle, but the shackle connecting the entire assembly to the hook bears the total lifted weight — 8,500 lbs. Each individual sling leg carries 8,500 / (2 × cos(22.5°)) ≈ 4,594 lbs due to the angle, but the shackle itself sees the full 8,500 lbs. Shackle WLL must be ≥ 8,500 lbs.

Question 87: A rolling offset must clear an obstruction using 45° elbows. The set (vertical rise) is 18 inches and the roll (horizontal side-shift) is 24 inches. What is the travel length of the diagonal offset pipe?

38.18 inches
30.00 inches
48.00 inches
42.43 inches (Correct answer)

Correct answer: 42.43 inches

A rolling offset requires two steps. First, find the true offset using the Pythagorean theorem: √(18² + 24²) = √(324 + 576) = √900 = 30 inches. This is a classic 3-4-5 right triangle scaled by 6. Then apply the 45° travel constant: 30 × 1.4142 = 42.43 inches. Choosing just 30 inches ignores the second step; 38.18 would result from incorrectly adding set and roll before applying the constant.

Question 88: When working in a confined space with potential oxygen deficiency, what minimum oxygen level must be present before entry without supplied air?

18%
21%
16%
19.5% (Correct answer)

Correct answer: 19.5%

OSHA requires a minimum atmospheric oxygen concentration of 19.5% before workers may enter a confined space without supplied-air respirators.

Question 89: On a plot plan, what do concentric circles with a letter/number designation typically represent?

Column north reference points (Correct answer)
Equipment nozzle locations
Pipe support anchor locations
Underground utility crossings

Correct answer: Column north reference points

Concentric circles with column designations on a plot plan represent the plant's column grid reference points (Column North).

Question 90: What is the OSHA minimum safe distance requirement for workers near energized overhead power lines at 50kV or below?

25 feet (7.6 meters)
10 feet (3 meters) (Correct answer)
6 feet (1.8 meters)
3 feet (1 meter)

Correct answer: 10 feet (3 meters)

OSHA 1926.1408 requires a minimum clearance of 10 feet from overhead power lines up to 50kV for cranes, equipment, and workers.

Question 91: What does the pipe material specification 'ASTM A53 Grade B Type S' indicate?

Grade B indicates the pipe is for below-grade (underground) installation
Type S means schedule and Grade B is the pressure rating
ASTM A53 covers welded and seamless black and galvanized steel pipe for general service; Grade B is the higher strength version; Type S designates Seamless manufacture (Correct answer)
Type S is a surface treatment code for galvanized coating

Correct answer: ASTM A53 covers welded and seamless black and galvanized steel pipe for general service; Grade B is the higher strength version; Type S designates Seamless manufacture

ASTM A53 covers both welded and seamless carbon steel pipe. Grade B is the higher tensile strength option (min 60 ksi tensile, 35 ksi yield). Type S designates Seamless; Type E designates Electric Resistance Welded; Type F is furnace-butt welded.

Question 92: Before a rigger uses a wire rope clip (U-bolt clip) to form an eye termination, the correct orientation requires:

The U-bolt saddle on the live (load) side of the rope
Both clips facing the same direction regardless of live/dead side
The U-bolt saddle on the dead (short) end of the rope (Correct answer)
The clip installed without lubricant to increase friction

Correct answer: The U-bolt saddle on the dead (short) end of the rope

The rule 'never saddle a dead horse' means the U-bolt (saddle) must bear on the dead (short) end, not the live load-bearing rope.

Question 93: When fabricating a piping system with polyvinyl chloride (PVC) pipe, what is the most common and recommended method for creating a permanent joint?

Compression fitting
Threaded connection with sealant
Solvent cementing (Correct answer)
Butt fusion

Correct answer: Solvent cementing

Solvent cementing is the standard and most widely used method for joining PVC and CPVC pipes and fittings. The process involves using a primer and solvent cement to chemically fuse the pieces together, creating a strong, permanent, and leak-proof joint.

Question 94: A rigging plan requires lifting a 4,000 lb load with a two-leg sling bridle where the slings are at a 60-degree angle from the horizontal. What is the approximate tension on each individual sling leg?

2,000 lbs
4,000 lbs
2,309 lbs (Correct answer)
2,828 lbs

Correct answer: 2,309 lbs

The formula for tension on each leg is (Total Load / Number of Legs) / sin(Angle). In this case, it is (4,000 lbs / 2) / sin(60°). Since sin(60°) is approximately 0.866, the calculation is 2,000 lbs / 0.866, which equals approximately 2,309 lbs per leg.

Question 95: When inspecting a synthetic web sling before use, which defect is an immediate disqualifier?

Fading of the label color from UV exposure
Any acid or caustic burns (Correct answer)
Slight stiffness from cold temperatures
Minor surface abrasion affecting less than 10% of sling width

Correct answer: Any acid or caustic burns

Any acid or caustic burns on a synthetic web sling require immediate removal from service as chemical damage compromises the entire sling.

Question 96: Which fitting is used to connect two pipes of different diameters in a straight run?

Tee
Reducer (Correct answer)
Elbow
Coupling

Correct answer: Reducer

A reducer connects two pipes of different diameters in-line and can be either concentric or eccentric depending on alignment requirements.

Question 97: A butterfly valve rated Class 150 is being evaluated for isolation service on a 10-inch water line operating at 150 psig. The pipefitter should:

Accept the valve — 150 psig matches the Class 150 pressure rating exactly
Reject the valve — the Class 150 rating at elevated temperatures may derate below 150 psig, and full-port isolation may be required per spec (Correct answer)
Accept the valve only if the actuator torque is verified against the differential pressure
Reject the valve — butterfly valves cannot provide bubble-tight shutoff

Correct answer: Reject the valve — the Class 150 rating at elevated temperatures may derate below 150 psig, and full-port isolation may be required per spec

ASME/ANSI Class 150 flanged ratings are temperature-dependent. At elevated temperatures, the allowable pressure drops well below 285 psig (the 100°F rating). Furthermore, many piping specifications require full-port block valves (gate or ball) for isolation service, excluding butterfly valves. The pipefitter must verify both the derated pressure at operating temperature and whether the line spec permits butterfly valves for isolation.

Question 98: A pipefitter is tasked with welding a branch connection on an active 2-inch natural gas service line using a hot-tap procedure. The line is at 15 psig operating pressure. Before the hot-tap machine is energized, which condition would be the most critical disqualifier requiring work stoppage?

The welder's hot-work permit was issued more than 4 hours ago
The branch outlet valve has not yet been installed on the fitting
Ambient temperature at the work site is above 90°F
The measured gas flow velocity in the line is below the minimum threshold specified by the hot-tap equipment manufacturer (Correct answer)

Correct answer: The measured gas flow velocity in the line is below the minimum threshold specified by the hot-tap equipment manufacturer

Minimum flow velocity is critical during hot-tap welding on gas lines because flow carries away heat generated by the weld. Insufficient velocity allows heat to concentrate at the weld zone, potentially overheating the pipe wall opposite the weld, causing burn-through, ignition of the gas, or metallurgical damage (especially on thin-wall pipe). Manufacturers specify minimum flow rates precisely to maintain the thermal balance that prevents catastrophic failure. This is a manufacturer-specified safety prerequisite — not a guideline — and its absence is an absolute stop-work condition.

Question 99: What does a double line on a piping flow diagram (PFD or P&ID) typically represent compared to a single line?

A larger or main process pipe versus an instrument or utility line (Correct answer)
A welded pipe versus a threaded pipe
A high-pressure line versus a low-pressure line
An underground pipe versus an above-grade pipe

Correct answer: A larger or main process pipe versus an instrument or utility line

Double lines on flow diagrams represent major process pipes, while single lines represent smaller instrument, sample, or utility connections.

Question 100: A pipefitter is preparing to make a full-penetration butt weld on 10-inch Schedule 120 P22 (2.25Cr-1Mo) alloy steel pipe using SMAW. The ambient temperature is 28°F (-2°C). The applicable WPS requires a minimum preheat of 300°F (149°C) and a maximum interpass temperature of 600°F (316°C). The root pass is completed at 350°F. When the pipefitter returns after a 45-minute break, the joint has cooled to 180°F. What is the correct procedure before depositing the next weld pass?

Continue welding immediately since 180°F is above ambient and hydrogen diffusion has continued during the break
Re-preheat the entire joint uniformly back to at least 300°F before continuing to weld (Correct answer)
Apply a localized torch heat to the weld groove only, bringing the groove area to 300°F while the pipe body remains cooler
Perform a PT examination of the root pass before reheating, then resume welding after confirming no cold cracking

Correct answer: Re-preheat the entire joint uniformly back to at least 300°F before continuing to weld

When the interpass temperature drops below the minimum preheat requirement (300°F for P22), the entire weld area — including a minimum of 3 inches on each side of the joint — must be uniformly re-preheated to the minimum preheat temperature before welding resumes. P22 is a hydrogen-cracking-susceptible alloy; the preheat requirement exists to slow cooling rates and allow hydrogen to diffuse out of the weld HAZ. Localized heating only at the groove would create steep thermal gradients and high residual stresses. Continuing to weld below minimum preheat risks hydrogen-induced cold cracking, which in P22 can occur hours after welding.

Certified Pipefitter Journeyman Exam

The Certified Pipefitter Journeyman Exam assesses competency in blueprint reading, pipe fabrication and joining, welding techniques, rigging and hoisting, safety codes, fluid mechanics, valve and fitting selection, and pipefitting mathematics required for journeyman certification.

100

Questions

180 min

Time Limit

70%

To Pass

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