Maryland Boiler Installer License Exam Practice 2026–2027
250 Challenging Questions with Answers & Detailed Explanations
Section 1: Maryland Licensing Law & Regulations (Questions 1–45)
1. Which Maryland board oversees boiler installer licensing for stationary
engineers?
A) Maryland Department of Public Safety
B) Board of Stationary Engineers under the Department of Labor
C) Maryland Department of the Environment
D) Maryland Building Codes Administration
Answer B: — Board of Stationary Engineers under the Department of Labor
Rationale: The Maryland Board of Stationary Engineers, operating under the
Department of Labor, oversees the licensing of boiler operators and stationary
engineers in the state. The Board administers a licensing program to ensure
that qualified individuals provide stationary engineer services, protect the
,public, provide for the safe operation of power plants, plants of machinery,
and boilers, and promote high professional standards. ---
2. How many grades of stationary engineer licenses does Maryland issue?
A) Five grades (1st through 5th Class)
B) Four grades (1st through 4th Class)
C) Three grades (1st through 3rd Class)
D) Two grades (engineer and apprentice)
Answer A: — Five grades (1st through 5th Class)
Rationale: Maryland issues five grades of stationary engineer licenses, from
1st Class (highest) through 5th Class (entry-level). The 1st Class license
authorizes operation of boilers of unlimited size. Each grade has specific
experience requirements and examination standards. ---
3. What is the primary function of a safety valve on a steam boiler?
A) To regulate the feedwater flow rate into the boiler
B) To prevent the boiler pressure from exceeding the maximum allowable
working pressure by automatically relieving steam
C) To control the combustion rate of the burner
D) To drain condensate from steam distribution lines
,Answer B: — To prevent the boiler pressure from exceeding the maximum
allowable working pressure by automatically relieving steam
Rationale: A safety valve is the most critical safety device on a steam boiler. It
automatically opens when the boiler pressure reaches the set point to release
steam and prevent the pressure from exceeding the MAWP. This protects the
boiler from overpressure and potential catastrophic failure. ---
4. What does "MAWP" stand for in boiler operations?
A) Minimum Acceptable Water Pressure
B) Maximum Allowable Working Pressure
C) Maximum Automatic Water Pump
D) Minimum Allowable Working Parameters
Answer B: — Maximum Allowable Working Pressure
Rationale: MAWP stands for Maximum Allowable Working Pressure, which is
the highest pressure at which a boiler is designed and rated to operate safely.
The MAWP is determined by the manufacturer during construction, stamped
on the boiler nameplate, and cannot be exceeded during operation. ---
5. In Maryland, what is required for all grades of stationary engineer
licenses?
A) Passing a state examination
, B) Completion of a university engineering degree
C) Completion of federal licensing exams only
D) Military engineering discharge certificate
Answer A: — Passing a state examination
Rationale: All grades of Maryland stationary engineer licenses require passing
a state examination with a score of at least 70%. The examination is
administered by PSI Examination Services. There are no exam exemptions for
any grade, though the examination is open-book for Grades 5 and 4. ---
6. What is the horsepower range for a Grade 5 stationary engineer license?
A) 30–99 HP in a building not open for public use
B) 30–99 HP in any building regardless of use
C) 100–299 HP in any building
D) 300–499 HP in any building
Answer A: — 30–99 HP in a building not open for public use
Rationale: A Grade 5 stationary engineer licensee may oversee the operation
of a boiler that can be operated at 30 to 99 horsepower and is located in a
building not open for public use. This is the entry-level license grade in
Maryland. ---
7. What is the horsepower range for a Grade 4 stationary engineer license?
250 Challenging Questions with Answers & Detailed Explanations
Section 1: Maryland Licensing Law & Regulations (Questions 1–45)
1. Which Maryland board oversees boiler installer licensing for stationary
engineers?
A) Maryland Department of Public Safety
B) Board of Stationary Engineers under the Department of Labor
C) Maryland Department of the Environment
D) Maryland Building Codes Administration
Answer B: — Board of Stationary Engineers under the Department of Labor
Rationale: The Maryland Board of Stationary Engineers, operating under the
Department of Labor, oversees the licensing of boiler operators and stationary
engineers in the state. The Board administers a licensing program to ensure
that qualified individuals provide stationary engineer services, protect the
,public, provide for the safe operation of power plants, plants of machinery,
and boilers, and promote high professional standards. ---
2. How many grades of stationary engineer licenses does Maryland issue?
A) Five grades (1st through 5th Class)
B) Four grades (1st through 4th Class)
C) Three grades (1st through 3rd Class)
D) Two grades (engineer and apprentice)
Answer A: — Five grades (1st through 5th Class)
Rationale: Maryland issues five grades of stationary engineer licenses, from
1st Class (highest) through 5th Class (entry-level). The 1st Class license
authorizes operation of boilers of unlimited size. Each grade has specific
experience requirements and examination standards. ---
3. What is the primary function of a safety valve on a steam boiler?
A) To regulate the feedwater flow rate into the boiler
B) To prevent the boiler pressure from exceeding the maximum allowable
working pressure by automatically relieving steam
C) To control the combustion rate of the burner
D) To drain condensate from steam distribution lines
,Answer B: — To prevent the boiler pressure from exceeding the maximum
allowable working pressure by automatically relieving steam
Rationale: A safety valve is the most critical safety device on a steam boiler. It
automatically opens when the boiler pressure reaches the set point to release
steam and prevent the pressure from exceeding the MAWP. This protects the
boiler from overpressure and potential catastrophic failure. ---
4. What does "MAWP" stand for in boiler operations?
A) Minimum Acceptable Water Pressure
B) Maximum Allowable Working Pressure
C) Maximum Automatic Water Pump
D) Minimum Allowable Working Parameters
Answer B: — Maximum Allowable Working Pressure
Rationale: MAWP stands for Maximum Allowable Working Pressure, which is
the highest pressure at which a boiler is designed and rated to operate safely.
The MAWP is determined by the manufacturer during construction, stamped
on the boiler nameplate, and cannot be exceeded during operation. ---
5. In Maryland, what is required for all grades of stationary engineer
licenses?
A) Passing a state examination
, B) Completion of a university engineering degree
C) Completion of federal licensing exams only
D) Military engineering discharge certificate
Answer A: — Passing a state examination
Rationale: All grades of Maryland stationary engineer licenses require passing
a state examination with a score of at least 70%. The examination is
administered by PSI Examination Services. There are no exam exemptions for
any grade, though the examination is open-book for Grades 5 and 4. ---
6. What is the horsepower range for a Grade 5 stationary engineer license?
A) 30–99 HP in a building not open for public use
B) 30–99 HP in any building regardless of use
C) 100–299 HP in any building
D) 300–499 HP in any building
Answer A: — 30–99 HP in a building not open for public use
Rationale: A Grade 5 stationary engineer licensee may oversee the operation
of a boiler that can be operated at 30 to 99 horsepower and is located in a
building not open for public use. This is the entry-level license grade in
Maryland. ---
7. What is the horsepower range for a Grade 4 stationary engineer license?
