20 Questions
What must operators do to ensure the safety and long life of boilers?
Pay attention to the warm-up rates prescribed by the boiler manufacturers
According to ASME VI Recommended Rules, what should operators do if abnormal conditions occur during the light-off or warm-up period?
Shut down the boiler immediately and close the main and pilot test firing valves
What is one of the conditions encountered during warm-up that may seem abnormal but should disappear after the boiler is hot?
Slight smoking
What should be done before restarting a boiler if abnormal conditions have occurred during warm-up?
Identify and correct the cause of the trouble
What is advised for operators of power boilers if abnormal conditions occur during startup?
Never restart the boiler before correcting the problem
What does ASME VI Recommended Rules advise operators to do if abnormal conditions occur during light-off or warm-up?
Shut down the boiler immediately and close the main and pilot test firing valves
What can cause flue gas condensation in a boiler?
Contact with cold heating surfaces
What can happen if a cold boiler is fired at too high a rate?
Thermal shock and refractory damage
How can uneven expansion in a boiler be worsened?
By scale buildup on heating surfaces
What is the result of thermal shock in the metal of a boiler?
Formation of tiny cracks
How can boilers be protected from thermal shock?
Warming up boilers slowly
What does flue gas condensation indicate in a boiler?
Contact with cold heating surfaces
What is the recommended maximum rate of increase in boiler water temperature for larger boilers during warm-up?
55°C per hour
What is a good indication of refractory damage during boiler warm-up?
Black, peeling paint on the metal surface
When should the water level control system for steam boilers be placed on automatic?
As soon as the boiler is ignited
What warning is given regarding leaving a boiler unattended during its warm-up period?
It may cause thermal shock to the metal and refractory
What is the purpose of continually monitoring the boiler while it is warming up and pressurizing?
To check for signs of poor combustion and hot spots on the metal surface
What should be done after the boiler pressure approaches its normal pressure or temperature set point during warm-up?
Switch the firing rate control to automatic
What should be done if combustion gases are not passing normally through the furnace and flue gas passages during warm-up?
Consult manufacturer specifications
What is important to prevent during the warm-up period of a boiler?
Thermal shock of the metal and refractory
Test your knowledge of the effects of rapid heating on boiler metal and the conditions encountered during warm-up. Learn about the importance of following warm-up rates prescribed by boiler manufacturers for safety and long life of boilers.
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