CITY OF OMAHA STATIONARY ENGINEER
FIRST GRADE 2026 ACTUAL TEST PAPER
QUESTIONS AND SOLUTIONS COMPLETE
REVIEW GRADED A+
⩥ Which type of heat transfer takes place by actual physical contact,
from molecule to molecule, without displacing the molecules?
Answer: Conduction
⩥ Which type of boiler is the most economical to build?
Answer: Firetube
⩥ A boiler is an industrial boiler when
Answer: The steam generated is used for a process
⩥ Which is true about an industrial boiler as compared to a utility
boiler?
Answer: Idustrial boilers operate at lower pressures and temperatures
⩥ Utility boilers are used primarily to produce
Answer: High pressure steam to drive turbines that make electricity
,⩥ Which of the following is NOT a type of fire tube boiler?
Answer: Stirling
⩥ Which of the following is an example of a cogeneration system?
Answer: Exhaust gases from a combustion turbine driven generator are
used to make steam in a boiler for a secondary purpose
⩥ If the tubes in a boiler are expanded during installation, which of the
following will
be true?
Answer: The ID is increased
⩥ When a new tube is installed in a firetube boiler, which of the
following happens to
the tube?
Answer: The tube is lengthened
⩥ What is the MINIMUM size of an elliptical manhole on a boiler?
Answer: 11" x 15"
⩥ What is the MINIMUM water temperature to be used for a hydrostatic
test?
Answer: 70 degrees F
,⩥ How many sq ft of heating surface are required to produce 1
horsepower in a HRT
firetube boiler?
Answer: 12 sq ft
⩥ How many sq ft of heating surface are required to produce 1
horsepower in a
vertical firetube boiler?
Answer: 14 sq ft
⩥ How many sq ft of heating surface are required to produce 1
horsepower in a
watertube boiler?
Answer: 10 sq ft
⩥ If a high pressure boiler is at its highest operating pressure below the
MAWP,
where will the pointer on the pressure gauge be?
Answer: at 12ʻ o clock
⩥ A gauge that reads higher than the actual boiler pressure is called a
Answer: Fast gauge
, ⩥ Which is true about a boiler pressure mercury switch?
Answer: Mercury switch must be installed with pigtail siphon vertically
⩥ On a low pressure boiler, cut out equals
Answer: cut in plus differential
⩥ What is the MAXIMUM blowback on a safety relief valve that is set
for 100 psig
Answer: 4 psig
⩥ If a high pressure boiler operates at 100 psig, what should be the
blowback of the
safety valve?
Answer: not more than 4% and not less then 2psi in any case
⩥ What is the MINIMUM blowback on a safety valve that pops at 250
psi.
Answer: 5 psi
⩥ A data plate on a safety valve on a low pressure boiler is marked
"6900 Ib".
This refers to:
FIRST GRADE 2026 ACTUAL TEST PAPER
QUESTIONS AND SOLUTIONS COMPLETE
REVIEW GRADED A+
⩥ Which type of heat transfer takes place by actual physical contact,
from molecule to molecule, without displacing the molecules?
Answer: Conduction
⩥ Which type of boiler is the most economical to build?
Answer: Firetube
⩥ A boiler is an industrial boiler when
Answer: The steam generated is used for a process
⩥ Which is true about an industrial boiler as compared to a utility
boiler?
Answer: Idustrial boilers operate at lower pressures and temperatures
⩥ Utility boilers are used primarily to produce
Answer: High pressure steam to drive turbines that make electricity
,⩥ Which of the following is NOT a type of fire tube boiler?
Answer: Stirling
⩥ Which of the following is an example of a cogeneration system?
Answer: Exhaust gases from a combustion turbine driven generator are
used to make steam in a boiler for a secondary purpose
⩥ If the tubes in a boiler are expanded during installation, which of the
following will
be true?
Answer: The ID is increased
⩥ When a new tube is installed in a firetube boiler, which of the
following happens to
the tube?
Answer: The tube is lengthened
⩥ What is the MINIMUM size of an elliptical manhole on a boiler?
Answer: 11" x 15"
⩥ What is the MINIMUM water temperature to be used for a hydrostatic
test?
Answer: 70 degrees F
,⩥ How many sq ft of heating surface are required to produce 1
horsepower in a HRT
firetube boiler?
Answer: 12 sq ft
⩥ How many sq ft of heating surface are required to produce 1
horsepower in a
vertical firetube boiler?
Answer: 14 sq ft
⩥ How many sq ft of heating surface are required to produce 1
horsepower in a
watertube boiler?
Answer: 10 sq ft
⩥ If a high pressure boiler is at its highest operating pressure below the
MAWP,
where will the pointer on the pressure gauge be?
Answer: at 12ʻ o clock
⩥ A gauge that reads higher than the actual boiler pressure is called a
Answer: Fast gauge
, ⩥ Which is true about a boiler pressure mercury switch?
Answer: Mercury switch must be installed with pigtail siphon vertically
⩥ On a low pressure boiler, cut out equals
Answer: cut in plus differential
⩥ What is the MAXIMUM blowback on a safety relief valve that is set
for 100 psig
Answer: 4 psig
⩥ If a high pressure boiler operates at 100 psig, what should be the
blowback of the
safety valve?
Answer: not more than 4% and not less then 2psi in any case
⩥ What is the MINIMUM blowback on a safety valve that pops at 250
psi.
Answer: 5 psi
⩥ A data plate on a safety valve on a low pressure boiler is marked
"6900 Ib".
This refers to:
