Career upgrade: Learn practical AI skills for better jobs and higher pay.
Level up
PracticeVideosBlogFlashcardsEspañol
All Practice Exams

100+ Free NIULPE 2nd Class Practice Questions

Pass your NIULPE 2nd Class Power Engineer exam on the first try — instant access, no signup required.

✓ No registration✓ No credit card✓ No hidden fees✓ Start practicing immediately
N/A Pass Rate
100+ Questions
100% Free
1 / 100
Question 1
Score: 0/0

A typical NIULPE 2nd Class Power Engineer is qualified to operate plants of what general size?

A
B
C
D
to track
Same family resources

Explore More NIULPE Power Engineer Certifications

Continue into nearby exams from the same family. Each card keeps practice questions, study guides, flashcards, videos, and articles in one place.

NIULPE 1st Class Power Engineer

Practice Questions

NIULPE 3rd Class Power Engineer

Practice Questions

NIULPE 4th Class Power Engineer

Practice Questions

NIULPE 5th Class Power Engineer

Practice Questions
2026 Statistics

Key Facts: NIULPE 2nd Class Exam

100

Questions

NIULPE

180 minutes

Exam Time

NIULPE

70%

Passing Score

NIULPE

500+ BHP

Typical Plant Size

NIULPE classification

NIULPE 2nd Class Power Engineer is the second-highest operator classification. It qualifies an engineer to operate large industrial boilers (typically 500+ BHP) and supervise lower-class operators. The 100-question, 3-hour exam covers advanced boiler operation, steam and turbine systems, refrigeration, water treatment, safety codes (ASME, NBIC, OSHA), and emergency response with a 70% pass mark.

Sample NIULPE 2nd Class Practice Questions

Try these sample questions to test your NIULPE 2nd Class exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1One boiler horsepower (BHP) is equivalent to how many Btu per hour?
A.12,000 Btu/hr
B.33,475 Btu/hr
C.100,000 Btu/hr
D.2,545 Btu/hr
Explanation: By ASME definition, 1 boiler horsepower equals 33,475 Btu/hr, which is also the heat required to evaporate 34.5 lb of water per hour from and at 212 degrees F at atmospheric pressure.
2One boiler horsepower also equals what evaporation rate at 212 degrees F?
A.10 lb of steam per hour
B.34.5 lb of steam per hour
C.100 lb of steam per hour
D.1,000 lb of steam per hour
Explanation: One BHP equals the evaporation of 34.5 lb of water per hour from and at 212 degrees F. This is the equivalent steaming rate definition tied to the 33,475 Btu/hr figure.
3Which boiler type uses hot gases flowing through tubes that are surrounded by water?
A.Water-tube boiler
B.Fire-tube boiler
C.Once-through boiler
D.Electric boiler
Explanation: In a fire-tube (Scotch marine, locomotive, or vertical) boiler, hot combustion gases flow through tubes submerged in water. Water-tube boilers do the opposite: water flows through tubes surrounded by hot gases.
4Which water-tube boiler configuration is characterized by a single steam drum on top, two mud drums at the bottom, and a wide furnace?
A.A-type
B.O-type
C.D-type
D.H-type
Explanation: The A-type water-tube boiler has one steam drum on top and two mud drums on the bottom forming an 'A' shape, providing a large furnace volume. D-type has the furnace on one side, O-type has a symmetric central furnace.
5Which feedwater control scheme uses drum level, steam flow, and feedwater flow as inputs?
A.Single-element control
B.Two-element control
C.Three-element control
D.On-off control
Explanation: Three-element feedwater control senses drum level, steam flow (load), and feedwater flow. It is the standard for large boilers with rapidly changing loads because it anticipates load changes and corrects shrink and swell.
6What is the typical excess air range for a properly tuned natural gas burner?
A.1 to 5 percent
B.10 to 15 percent
C.30 to 40 percent
D.50 to 60 percent
Explanation: Natural gas burns cleanly and typically requires only 10 to 15 percent excess air. Oil burners need 15 to 20 percent and coal commonly 20 to 30 percent. Too much excess air wastes heat up the stack.
7Which BMS phase removes any residual combustible gases from the furnace before any ignition attempt?
A.Post-purge
B.Pre-purge
C.Pilot trial for ignition
D.Main flame trial
Explanation: Pre-purge moves at least four furnace volumes of air through the boiler before any ignition attempt to remove any combustible residue. It is required by NFPA 85 and is the first phase of the BMS sequence.
8A flame safeguard detects loss of flame. What is the maximum allowable flame failure response time under NFPA 85 for most industrial burners?
A.0.5 seconds
B.4 seconds
C.30 seconds
D.60 seconds
Explanation: NFPA 85 requires a flame failure response time of no more than 4 seconds for most industrial burners. The flame safeguard must initiate a safety shutdown of fuel within that interval.
9Which oil burner atomization method uses high-pressure steam to break up the fuel oil?
A.Mechanical (pressure) atomization
B.Steam atomization
C.Rotary cup atomization
D.Ultrasonic atomization
Explanation: Steam atomization injects high-pressure steam into the oil stream at the tip, shearing the oil into fine droplets. It is common on large industrial boilers because it gives a wide turndown ratio and clean combustion.
10A McDonnell-Miller 150 low water cutoff is what type of device?
A.Probe (conductance) type
B.Float (magnetic) type
C.Differential pressure type
D.Ultrasonic type
Explanation: The McDonnell-Miller 150 series is a float-actuated low water cutoff. A magnetic float linkage operates a mercury switch or a snap-action switch to interrupt the burner circuit when the water drops below a safe level.

About the NIULPE 2nd Class Exam

The NIULPE 2nd Class Power Engineer exam tests the advanced operational knowledge required to run medium-to-large industrial boilers and auxiliary equipment with limited or no supervision, typically including plants above 500 boiler horsepower.

Questions

100 scored questions

Time Limit

180 minutes

Passing Score

70%

Exam Fee

$150 - $300 (National Institute for the Uniform Licensing of Power Engineers (NIULPE))

NIULPE 2nd Class Exam Content Outline

30%

Boiler Operation and Auxiliaries

Advanced operation of large fire-tube and water-tube boilers, BMS sequences, feedwater control, combustion control, economizers, and air preheaters

20%

Steam and Turbine Systems

Steam properties, superheaters, attemperators, steam turbines, governors, condensate systems, and vacuum equipment

15%

Refrigeration, HVAC, and Auxiliary Plant

Chillers, cooling towers, heat exchangers, pumps, refrigerants, and auxiliary plant operation

10%

Water Treatment and Chemistry

Internal and external treatment, blowdown control, testing procedures, and condensate corrosion control

15%

Safety, Codes, and Emergency Procedures

ASME Section I/IV/VIII, NBIC, OSHA 1910, LOTO, confined space, emergency shutdown, and low water response

10%

Maintenance, Inspection, and Records

PSV testing, internal/external inspections, log keeping, tube cleaning, and predictive maintenance

How to Pass the NIULPE 2nd Class Exam

What You Need to Know

  • Passing score: 70%
  • Exam length: 100 questions
  • Time limit: 180 minutes
  • Exam fee: $150 - $300

Keys to Passing

  • Complete 500+ practice questions
  • Score 80%+ consistently before scheduling
  • Focus on highest-weighted sections
  • Use our AI tutor for tough concepts

NIULPE 2nd Class Study Tips from Top Performers

1Master BHP calculations: 1 BHP equals 33,475 Btu/hr or 34.5 lb/hr of steam at 212 degrees F.
2Memorize feedwater control schemes (single, two, and three-element) and when each is appropriate.
3Learn the Burner Management System sequence end-to-end: pre-purge, pilot trial, main flame trial, run, and post-purge.
4Practice reading saturated steam tables and understand the difference between saturated and superheated steam.
5Know steam trap types and their typical failure modes (F&T, inverted bucket, thermostatic, thermodynamic).
6Drill on ASME Section I vs Section IV applicability and PSV testing/inspection intervals.

Frequently Asked Questions

What does a NIULPE 2nd Class Power Engineer license allow you to do?

A NIULPE 2nd Class Power Engineer is qualified to operate medium-to-large industrial boilers and auxiliary equipment (typically 500+ BHP) with limited or no supervision and to supervise lower-class operators. It is the second-highest operator classification recognized by NIULPE.

How many questions are on the NIULPE 2nd Class exam and how long is it?

The NIULPE 2nd Class Power Engineer exam has 100 multiple-choice questions and a 3-hour (180-minute) time limit. A passing score of approximately 70% is required.

What are the prerequisites for the NIULPE 2nd Class exam?

Candidates typically must hold a current NIULPE 3rd Class license (or equivalent) and document a required number of hours of supervised operating experience on qualifying boilers and auxiliary plant equipment. Specific hours and documentation vary by jurisdiction and chapter.

How is the NIULPE 2nd Class different from the 1st Class exam?

The 2nd Class exam focuses on hands-on operation of large boilers and auxiliaries, while the 1st Class exam adds more depth on chief-engineer-level supervision, plant management, advanced thermodynamics, and complex multi-unit plant operation.