GUIDE QUESTIONS
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? ...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.
How do you determine whether feedwater check valve for the boiler is not closing? ...ANSWER...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? ...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.
What is boiler priming? What causes priming? How can priming in a boiler damage an engine or
pump? ...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)
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? ...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.
How do you test a safety valve to see if it operates at the proper set pressure? What is the difference
between a safety valve and a relief valve? How often do you test these valves? How is leaking safety
valve repaired? ...ANSWER...Pressure valves can be tested hydrostatically (boiler filled up with water
pressure).Safety valves open instantaneously and relief valves do not open fully with a set
pressure.Safety valves are tested manually once a month and pressure tested once a year.Safety valves
can be only repaired by a manufacturer or an authorized company.