STATIONARY ENGINEER 2026 STUDY GUIDE QUESTIONS
AND SOLUTIONS RATED A+
✔✔A blister is caused by what ? - ✔✔Slag inclusion forming a lamination at the time the
plate was rolled at the steel mill. A blister is a separation of the metal from the shell
plate caused by impurities rolled into the shell plate when formed.
✔✔With normal oxygen and low alkalinity. what is added to the boiler water? -
✔✔Neutralizing Amines
✔✔Which chemical is used to combat scale? - ✔✔Combined phosphate treatment-
sodium phosphate
✔✔Other than sulfite what chemical is used to combat corrosion in boilers? -
✔✔Hydrazine
✔✔What will neutralize acid? - ✔✔Alkali and Lime Soda
✔✔What mechanical device is used to remove scale from firetubes? - ✔✔A tube rattler
or vibrator
✔✔What percentage of the pressure should a boiler have before you test the lever of a
safety valve? - ✔✔75%
✔✔Where is internal corrosion most likely to occur on a vertical tube boiler? - ✔✔Water
leg-Mud leg
✔✔What are the minimum and maximum sizes permitted for blow down valves or
connections? - ✔✔3/4"minimum 2 ½ " maximum
✔✔A boiler operating at a pressure of 65lbs. What is the smallest size feed and blow off
connections if the safety valve is set at 90 psi? - ✔✔½ " feed ¾ " blow off
✔✔How often should water columns and water glass levels be checked on a high
pressure boiler? - ✔✔(Once A Shift)\nAt the beginning of each shift - beginning of the
work effort
✔✔What takes no actual action chemical part in combustion? - ✔✔Nitrogen
✔✔How many ppm of EDTA are needed to tie up 1ppm of hardness? - ✔✔EDTA
requires 10ppm of EDTA and 5 NTA to tie up each 1ppm hardness.
,✔✔On a package boiler; how many ways could cause fire puffs when it is started up? -
✔✔6 ways 1-poor starting draft 2-incorrect firebox 3-wrong burner nozzle 4-lean fire 5-
insufficient gas pilot or excessive gas pilot 6-water in the oil
✔✔What is the grade of light domestic fuel oil ? - ✔✔Grade 1 ( Number 1 )
✔✔How often should you test the operating control? - ✔✔Annually
✔✔How often should the testing and inspecting of the burner component? -
✔✔Annually
✔✔A lead sulfite photocell is what type of flame sensor? - ✔✔Infrared light sensing
✔✔What is the least amount of oxygen needed when a nitrogen blanket is used? -
✔✔19%
✔✔How should a boiler be prepared for inspection? - ✔✔Extinguish fire and allow boiler
to cool slowly. Open the blow down and the drain; vent the boiler to the atmosphere
Soot and ashes should be removed from all tubes; shell plates; heads; seams and
every accessible external surface. The blow down should be shut if any other boiler
feeds this line. Manhole - handhole plates and inspection plugs should be removed. All
loose deposits of sludge or sediment should be washed out. The blow down should only
be opened when it is certain that there is no pressure in the line and no one is inside the
boiler. Any scale or oil deposits should be left for the water treatment specialist to see
for analysis. A boiler properly prepared for inspection should be cool; dry and clean. It is
advisable to attach a red tag marked "person in boiler" to the steam; blowdown; feed
and fuel valves and also to the manhole plate whenever someone is inside a boiler.
✔✔What function can a boiler operator contribute to boiler maintenance? - ✔✔A)
maintain a safe reliable plant B) maintenance and efficient plant C) Inspection and
logging of items that need to be corrected during the next maintenance period
✔✔What are manholes and handholes on a boiler for? - ✔✔Examination or cleaning
✔✔How do you protect a steam boiler? - ✔✔Safety valve
✔✔How to you protect a pressure vessel? - ✔✔Pressure relief valve
✔✔How do you protect a hot water boiler? - ✔✔Pressure relief valve
✔✔What gages are on a steam boiler? - ✔✔Water gage glass and pressure gage
,✔✔Methods used to control the temperature of a superheater? - ✔✔Bypass damper -
spray-type desuperheater - attemperator - condenser - tilting burner - flue gas
recirculation
✔✔What chemical would you use to prevent hard scale from forming in the boiler
tubes? - ✔✔Disodium phosphate and trisodium phosphate
✔✔What chemical compounds in water cause permanent hardness? - ✔✔Calcium
sulfate and magnesium sulfate
✔✔What factors must be taken into consideration when choosing a control for a boiler?
- ✔✔6 factors 1. Steam pressure 2. Furnace pressure and draft 3. air pressure and flow
4. feed water pressure and flow 5. Flue gas flow & composition 6. proper ignition &
burner - flame control
✔✔How many safety controls shut down a boiler when an unsafe condition occurs? -
✔✔7 controls 1. Pressure limit or temperature 2. Low water fuel cutoffs 3. Flame failure
safeguard systems 4. Automatic ignition controls 5. oil and gas fuel shutoffs/valve
controls 6. air and fuel pressure interlock controls 7. feed water regulating controls
✔✔In a steam generating system what is blamed on chemical treatment but is in fact
part of a boiler design? - ✔✔Poor circulation
✔✔Class A Fires??? - ✔✔Wood - sawdust - paper - rags
✔✔Class B Fires?? - ✔✔Flammable liquids - oils - tars and gasses
✔✔Class C Fires?? - ✔✔Electrical equipment
✔✔What is the minimum clearance required when a boilers capacity is 5 000btus hr
over 1000sq ft heating surface or an imput over 5 000 000 btus hr? - ✔✔7 feet
✔✔Under what code are oil fired boilers and their control systems covered? - ✔✔O.F.B
726
✔✔A data plate has what information?? - ✔✔manufacturer - model serial number -
stamp of approval
✔✔When working in a boiler work permits should be aquired when? - ✔✔For Each Shift
✔✔ASME code requires that a LWCO control be tested by evaporation how often?? -
✔✔Monthly
, ✔✔ASME CSD1 requires the main gas burner to have what? - ✔✔2 manual shutoff
valves. pg 81 1004.1 code book
✔✔A HYDROSTATIC test is done at what pressure? - ✔✔1.5 times the MAWP or 50%
over MAWP
✔✔How many low water cutoff are needed per code on a hot water system? - ✔✔One
LWCO is needed when the boiler input is greater than 400 000 btus
✔✔What gages are on a steam boiler? - ✔✔pressure gage - water gage glass
✔✔What gages are on a HW boiler? - ✔✔pressure - Temp
✔✔Name three types of low water cutoffs. - ✔✔1. float magnetic (rod to magnet to
mercury switch) 2. Float linkage- link to mercury switch 3. Submerged electrode- water
✔✔Boilers having more than 500square feet of heating surface should have how many
means of feed water? - ✔✔2
✔✔Types of FEEDWATER REGULATORS - ✔✔1.Thermostatic mechanical regulator 2.
Thermostatic fluid style 3. Float operated style
✔✔Name two types of commonly used feedwater pumps - ✔✔Injector and Inspirator
✔✔What piping arrangment is used to return condensate from steam lines and steam
seperators? - ✔✔HOLLYLOOP
✔✔What would happen if high temp liquid passes through a centrifugal pump? -
✔✔WIRE DRAWING
✔✔A multi stage pump can be either __________ or_______ ? - ✔✔Volute or Diffuser
✔✔To prevent cavitation most pumps are stamped with the ____ _______ _______
____ ? - ✔✔NET POSITIVE SUCTION HEAD
✔✔What are two types of condensate return systems?? - ✔✔a.) Mechanical Return ;
uses steam traps and pumps to aid return b.) Gravity Return System : uses gravity
✔✔TO PREVENT THE SUPERHEATER FROM OVERHEATING ON START UP
WHAT SHOULD YOU DO - ✔✔EITHER FLOOD THE TUBES WITH WATER OR THE
SUPERHEATER SHOULD BE VENTED TO THE ATMOSPHERE BY A FREE BLOW
VALVE UNTIL THE BOILER GOES ON LINE.
AND SOLUTIONS RATED A+
✔✔A blister is caused by what ? - ✔✔Slag inclusion forming a lamination at the time the
plate was rolled at the steel mill. A blister is a separation of the metal from the shell
plate caused by impurities rolled into the shell plate when formed.
✔✔With normal oxygen and low alkalinity. what is added to the boiler water? -
✔✔Neutralizing Amines
✔✔Which chemical is used to combat scale? - ✔✔Combined phosphate treatment-
sodium phosphate
✔✔Other than sulfite what chemical is used to combat corrosion in boilers? -
✔✔Hydrazine
✔✔What will neutralize acid? - ✔✔Alkali and Lime Soda
✔✔What mechanical device is used to remove scale from firetubes? - ✔✔A tube rattler
or vibrator
✔✔What percentage of the pressure should a boiler have before you test the lever of a
safety valve? - ✔✔75%
✔✔Where is internal corrosion most likely to occur on a vertical tube boiler? - ✔✔Water
leg-Mud leg
✔✔What are the minimum and maximum sizes permitted for blow down valves or
connections? - ✔✔3/4"minimum 2 ½ " maximum
✔✔A boiler operating at a pressure of 65lbs. What is the smallest size feed and blow off
connections if the safety valve is set at 90 psi? - ✔✔½ " feed ¾ " blow off
✔✔How often should water columns and water glass levels be checked on a high
pressure boiler? - ✔✔(Once A Shift)\nAt the beginning of each shift - beginning of the
work effort
✔✔What takes no actual action chemical part in combustion? - ✔✔Nitrogen
✔✔How many ppm of EDTA are needed to tie up 1ppm of hardness? - ✔✔EDTA
requires 10ppm of EDTA and 5 NTA to tie up each 1ppm hardness.
,✔✔On a package boiler; how many ways could cause fire puffs when it is started up? -
✔✔6 ways 1-poor starting draft 2-incorrect firebox 3-wrong burner nozzle 4-lean fire 5-
insufficient gas pilot or excessive gas pilot 6-water in the oil
✔✔What is the grade of light domestic fuel oil ? - ✔✔Grade 1 ( Number 1 )
✔✔How often should you test the operating control? - ✔✔Annually
✔✔How often should the testing and inspecting of the burner component? -
✔✔Annually
✔✔A lead sulfite photocell is what type of flame sensor? - ✔✔Infrared light sensing
✔✔What is the least amount of oxygen needed when a nitrogen blanket is used? -
✔✔19%
✔✔How should a boiler be prepared for inspection? - ✔✔Extinguish fire and allow boiler
to cool slowly. Open the blow down and the drain; vent the boiler to the atmosphere
Soot and ashes should be removed from all tubes; shell plates; heads; seams and
every accessible external surface. The blow down should be shut if any other boiler
feeds this line. Manhole - handhole plates and inspection plugs should be removed. All
loose deposits of sludge or sediment should be washed out. The blow down should only
be opened when it is certain that there is no pressure in the line and no one is inside the
boiler. Any scale or oil deposits should be left for the water treatment specialist to see
for analysis. A boiler properly prepared for inspection should be cool; dry and clean. It is
advisable to attach a red tag marked "person in boiler" to the steam; blowdown; feed
and fuel valves and also to the manhole plate whenever someone is inside a boiler.
✔✔What function can a boiler operator contribute to boiler maintenance? - ✔✔A)
maintain a safe reliable plant B) maintenance and efficient plant C) Inspection and
logging of items that need to be corrected during the next maintenance period
✔✔What are manholes and handholes on a boiler for? - ✔✔Examination or cleaning
✔✔How do you protect a steam boiler? - ✔✔Safety valve
✔✔How to you protect a pressure vessel? - ✔✔Pressure relief valve
✔✔How do you protect a hot water boiler? - ✔✔Pressure relief valve
✔✔What gages are on a steam boiler? - ✔✔Water gage glass and pressure gage
,✔✔Methods used to control the temperature of a superheater? - ✔✔Bypass damper -
spray-type desuperheater - attemperator - condenser - tilting burner - flue gas
recirculation
✔✔What chemical would you use to prevent hard scale from forming in the boiler
tubes? - ✔✔Disodium phosphate and trisodium phosphate
✔✔What chemical compounds in water cause permanent hardness? - ✔✔Calcium
sulfate and magnesium sulfate
✔✔What factors must be taken into consideration when choosing a control for a boiler?
- ✔✔6 factors 1. Steam pressure 2. Furnace pressure and draft 3. air pressure and flow
4. feed water pressure and flow 5. Flue gas flow & composition 6. proper ignition &
burner - flame control
✔✔How many safety controls shut down a boiler when an unsafe condition occurs? -
✔✔7 controls 1. Pressure limit or temperature 2. Low water fuel cutoffs 3. Flame failure
safeguard systems 4. Automatic ignition controls 5. oil and gas fuel shutoffs/valve
controls 6. air and fuel pressure interlock controls 7. feed water regulating controls
✔✔In a steam generating system what is blamed on chemical treatment but is in fact
part of a boiler design? - ✔✔Poor circulation
✔✔Class A Fires??? - ✔✔Wood - sawdust - paper - rags
✔✔Class B Fires?? - ✔✔Flammable liquids - oils - tars and gasses
✔✔Class C Fires?? - ✔✔Electrical equipment
✔✔What is the minimum clearance required when a boilers capacity is 5 000btus hr
over 1000sq ft heating surface or an imput over 5 000 000 btus hr? - ✔✔7 feet
✔✔Under what code are oil fired boilers and their control systems covered? - ✔✔O.F.B
726
✔✔A data plate has what information?? - ✔✔manufacturer - model serial number -
stamp of approval
✔✔When working in a boiler work permits should be aquired when? - ✔✔For Each Shift
✔✔ASME code requires that a LWCO control be tested by evaporation how often?? -
✔✔Monthly
, ✔✔ASME CSD1 requires the main gas burner to have what? - ✔✔2 manual shutoff
valves. pg 81 1004.1 code book
✔✔A HYDROSTATIC test is done at what pressure? - ✔✔1.5 times the MAWP or 50%
over MAWP
✔✔How many low water cutoff are needed per code on a hot water system? - ✔✔One
LWCO is needed when the boiler input is greater than 400 000 btus
✔✔What gages are on a steam boiler? - ✔✔pressure gage - water gage glass
✔✔What gages are on a HW boiler? - ✔✔pressure - Temp
✔✔Name three types of low water cutoffs. - ✔✔1. float magnetic (rod to magnet to
mercury switch) 2. Float linkage- link to mercury switch 3. Submerged electrode- water
✔✔Boilers having more than 500square feet of heating surface should have how many
means of feed water? - ✔✔2
✔✔Types of FEEDWATER REGULATORS - ✔✔1.Thermostatic mechanical regulator 2.
Thermostatic fluid style 3. Float operated style
✔✔Name two types of commonly used feedwater pumps - ✔✔Injector and Inspirator
✔✔What piping arrangment is used to return condensate from steam lines and steam
seperators? - ✔✔HOLLYLOOP
✔✔What would happen if high temp liquid passes through a centrifugal pump? -
✔✔WIRE DRAWING
✔✔A multi stage pump can be either __________ or_______ ? - ✔✔Volute or Diffuser
✔✔To prevent cavitation most pumps are stamped with the ____ _______ _______
____ ? - ✔✔NET POSITIVE SUCTION HEAD
✔✔What are two types of condensate return systems?? - ✔✔a.) Mechanical Return ;
uses steam traps and pumps to aid return b.) Gravity Return System : uses gravity
✔✔TO PREVENT THE SUPERHEATER FROM OVERHEATING ON START UP
WHAT SHOULD YOU DO - ✔✔EITHER FLOOD THE TUBES WITH WATER OR THE
SUPERHEATER SHOULD BE VENTED TO THE ATMOSPHERE BY A FREE BLOW
VALVE UNTIL THE BOILER GOES ON LINE.
