Answers
Question 1
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 Answer
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.
Question 2
How do you determine whether feedwater check valve for the boiler is not closing?
Correct Answer
Check the temperature differential at the check valve when feedwater pump is not in operation.
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, Question 3
What causes foaming in the boiler? How would you know when a boiler is foaming? How do you stop foaming in a boiler?
Correct Answer
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.
Question 4
What is boiler priming? What causes priming? How can priming in a boiler damage an engine or pump?
Correct Answer
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)
Question 5
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 Answer
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.
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