ENGINEER LICENSE EXAM) QUESTIONS| WITH
COMPLETE SOLUTIONS
What are the precautions to be observed when starting any boiler that has been closed dow overnight?
Are there any special precautions required starting a gas burning boiler? - CORRECT ANSWERS
Make a physical observation of the boiler and its systems, walk around the boilerto check for any
abnormal conditions such as flammable material at the dampers, fuel leaks,damaged electrical conduits,
etc. Check all boiler systems (feedwater, fuel, etc). Very important issue in starting a gas firing boiler is a
furnace prepurge. It is never has to be altered or bypassed.
How do you determine whether feedwater check valve for the boiler is not closing? - CORRECT
ANSWERS Check the temperature differential at the check valve when feedwater pump is not in
operation.
What causes foaming in the boiler? How would you know when a boiler is foaming? How do you stop
foaming in a boiler? - CORRECT ANSWERS High TDS, organic matter and oil in the boiler cases
foaming. If the water level in the gage glass fluctuates, the most probable cause of thisis foaming. We
reduce amount of TDS by continuous and bottom blowdowns;we use anti-foaming chemicals to prevent
foaming.
What is boiler priming? What causes priming? How can priming in a boiler damage an engine or pump? -
CORRECT ANSWERS When the liquid water from the boiler drum gets to the steam lines it called
priming. Priming can be caused by boiler drum level excessively high, by foaming, sudden pressure
drop,and firing ratebeing to high. Priming causes water hammer that could destroy or shorten the life
expectancy of a load (mechanical damage)
What would you do if the pressure gauge on the boiler registers 150 psi and you knew that the safety
valve was set to open at 100 psi? - CORRECT ANSWERS Most likely pressure gage failed. In order
to get such excessive pressure both operating and high pressure limit controls have to fail also, plus the
safety valve. Also, if the boiler was over pressurized to such extent, it would give some indications such
as excessive vibration and abnormal sounds.Pressure gage can be quickly isolated and changed.