3RD CLASS STATIONARY STEAM ENGINEER
EXAMPREP STUDY GUIDE 2026 DETAILED
QUESTIONS AND CORRECT ANSWERS
GRADED A+
●● What is used to allow for expansion and contraction of the main
steam line? Answer: Expansion bends.
●● What is the procedure to replace a tubular gauge glass with the boiler
in service? Answer: Secure steam and water, open blowdown valve,
remove nuts and washers, check for broken glass, install new gauge
glass, tighten nuts, warm up glass, check for leaks.
●● When must a boiler have two main steam stop valves according to
ASME code? Answer: When high-pressure boilers in battery have a
manhole opening.
●● What type of valves may be used as main steam stop valves?
Answer: OS&Y gate valves or an automatic nonreturn valve.
●● Why does a boiler safety valve pop open rather than open slowly?
Answer: To prevent exceeding MAWP, it must open fully due to the
huddling chamber design.
, ●● What is an automatic nonreturn valve? Answer: It cuts a boiler in on-
line automatically and prevents steam drainage in case of failure.
●● What is the purpose of an air heater? Answer: To increase
combustion efficiency by supplying preheated air and to extend the life
of firebrick and refractory.
●● What are the two basic types of air heaters? Answer: Convection and
regenerative air heaters.
●● How is a hydrostatic test performed? Answer: Secure valves, drain,
fill with water, pressurize, check for leaks, and restore system.
●● What should be checked after performing a hydrostatic test? Answer:
Look for leaks or bulging of metal.
●● What is the function of the huddling chamber in a safety valve?
Answer: It provides steam pressure with a larger area to increase upward
force to open the valve.
●● What happens when the steam pressure on the incoming boiler is
higher than the line pressure? Answer: The automatic nonreturn valve
will cut the boiler in on-line.
EXAMPREP STUDY GUIDE 2026 DETAILED
QUESTIONS AND CORRECT ANSWERS
GRADED A+
●● What is used to allow for expansion and contraction of the main
steam line? Answer: Expansion bends.
●● What is the procedure to replace a tubular gauge glass with the boiler
in service? Answer: Secure steam and water, open blowdown valve,
remove nuts and washers, check for broken glass, install new gauge
glass, tighten nuts, warm up glass, check for leaks.
●● When must a boiler have two main steam stop valves according to
ASME code? Answer: When high-pressure boilers in battery have a
manhole opening.
●● What type of valves may be used as main steam stop valves?
Answer: OS&Y gate valves or an automatic nonreturn valve.
●● Why does a boiler safety valve pop open rather than open slowly?
Answer: To prevent exceeding MAWP, it must open fully due to the
huddling chamber design.
, ●● What is an automatic nonreturn valve? Answer: It cuts a boiler in on-
line automatically and prevents steam drainage in case of failure.
●● What is the purpose of an air heater? Answer: To increase
combustion efficiency by supplying preheated air and to extend the life
of firebrick and refractory.
●● What are the two basic types of air heaters? Answer: Convection and
regenerative air heaters.
●● How is a hydrostatic test performed? Answer: Secure valves, drain,
fill with water, pressurize, check for leaks, and restore system.
●● What should be checked after performing a hydrostatic test? Answer:
Look for leaks or bulging of metal.
●● What is the function of the huddling chamber in a safety valve?
Answer: It provides steam pressure with a larger area to increase upward
force to open the valve.
●● What happens when the steam pressure on the incoming boiler is
higher than the line pressure? Answer: The automatic nonreturn valve
will cut the boiler in on-line.
