276 Questions
What is the primary reason for monitoring boiler warm-up rates?
To prevent leaks and premature boiler failure
What should an operator do if abnormal conditions occur during the light-off or warm-up period?
Shutdown the boiler immediately and close the main and pilot test firing valves
What is a typical condition encountered during the warm-up period of a boiler?
Slight smoking
Why is it important to correct the cause of trouble before restarting the boiler?
To prevent further damage to the boiler
What is the recommended course of action if a boiler operator encounters abnormal conditions during startup?
Shutdown the boiler and restart once the issue is resolved
What is the purpose of the ASME VI Recommended Rules for the Care and Operation of Heating Boilers?
To establish safety protocols for boiler operation
Why does combustion not occur immediately when fuel oil is introduced into the furnace?
The furnace temperature is not yet high enough to vaporize the fuel oil
What is the result of high firing rates when starting a cold firetube boiler?
Thermal shock and refractory damage
What occurs when the water vapour in the flue gases contacts the cold heating surfaces of the boiler?
Flue gas condensation
Why is condensation more likely to occur in firetube boilers?
Due to their large water content
What is the result of uneven expansion in a cold firetube boiler?
Leakage and premature boiler failure
What causes the temperature differential in a cold firetube boiler?
The furnace and the first pass of the firetubes heating up more quickly
What is the effect of scale buildup on the furnace and firetubes?
Insulation of the furnace tube and firetubes from the cooling effect of the boiler water
What is thermal shock?
Strong internal stress caused by sudden temperature change
Why should a heavily smoking burner not be given additional combustion air?
It may create an explosive condition
What should be done if smoking persists after the boiler is warmed up?
Take the burner out of service
What is the primary cause of thermal shock in boilers?
Cold water introduction to a hot boiler
What is the recommended rate of boiler water temperature increase to prevent thermal shock?
55°C per hour
What is likely to occur if a cold boiler is started up and the maximum firing rate is applied?
The boiler will experience thermal shock and potentially form cracks
What is a common source of cold water that can cause thermal shock in steam heating boilers?
All of the above
Why is it important to warm up boilers slowly?
To prevent thermal shock and uneven expansion
What is the primary reason for keeping boilers free from scale buildup?
To prevent thermal shock and uneven expansion
What should be done when starting up a hot water heating system?
Bypass part of the flow around the boiler until the water temperature difference has reached its normal operating value
What is the recommended firing rate control during the warm-up period?
Manual low-fire control
What should be monitored during the warm-up and pressurizing period?
The flame pattern, water level control system, and refractory damage
What is the purpose of the 55°C per hour warm-up rate?
To minimize thermal shock and permit reasonable rates of thermal expansion
What is the purpose of checking the furnace draft pressures during boiler startup?
To verify that combustion gases are passing normally through the furnace and flue gas passages
Why should the boiler operator never leave a boiler unattended during its warm-up period?
To monitor the boiler and stay alert in case operator intervention is required
What is the first step in starting a hot water boiler?
Prepare the boiler plant auxiliaries according to site-specific procedures
What is the purpose of the 5-minute purge period in a gas-fired atmospheric burner?
To allow the furnace to purge naturally with the pilot and main gas valves shut
What should the operator do after the pilot flame is established in a gas-fired atmospheric burner?
Open the main burner test firing valve
What is the purpose of the air damper in a power burner system?
To control the combustion air flow to the boiler
What happens after the air damper fully opens in a power burner system?
The boiler will purge for a given time period
What is the purpose of the igniter in a power burner system?
To spark the pilot fuel to light the pilot flame
What should the operator do after the boiler pressure approaches its normal pressure or temperature set point?
Switch the firing rate control to automatic
What should the operator enter in the daily log after the boiler startup is complete?
A summary of the startup events
What is the recommended approach to warm up the steam lines and headers in a single boiler steam plant?
Warming up the steam lines and headers simultaneously with the boiler
What is the purpose of keeping the boiler steam outlet valve open during the warm-up period?
To allow the steam piping to warm up and pressurize at the same rate as the boiler
What is the recommended valve configuration when warming up a steam header or main?
Open the boiler stop, header stop, and drain valves
What is the purpose of the low point drains, steam traps, and steam trap bypass lines during the warm-up period?
To remove condensate from the header and steam main
What is the result of the steam entering the cold steam piping during the warm-up period?
The steam will condense heavily at first, but decreasingly as the steam piping comes up to temperature
What is the recommended approach to starting a cold boiler?
Open the inlet valve to the cold boiler, and then crack open the outlet valve
What is the purpose of the simultaneous warm-up procedure in a single boiler steam heating system?
To warm up the steam piping and boiler at the same rate
What is the type of valve usually found at the outlet of the boiler in a single power boiler plant?
Standard gate valve
What is the purpose of the header stop valve in a single power boiler plant?
It is not a required valve in single boiler installations
What is the recommended time to switch a boiler from low-fire to high-fire or automatic?
After the boiler has been warmed up, and is sufficiently warmed up
What should be done after the pilot ignition trial is over?
Open the main burner safety shut-off valves and ensure a stable flame
Why should the boiler be fired at low fire during the warm-up period?
To reduce the differential expansion between the furnace tube and firetubes
What should be checked frequently during the warm-up period?
The boiler for leaks
What should be done before increasing the fuel input rate?
Ensure the entire water content of the system and boiler has reached its normal operating temperature and pressure
What is the purpose of checking the tridicator gauge during the warm-up period?
To confirm the heating system is full
What should be done when the boiler shuts down?
Check the water pressure on the tridicator gauge
What is the purpose of the log book in the boiler operation?
To document the startup process and any corrective actions taken
What is the term used to describe the activity of adding a previously non-operating boiler to a system that is already in operation?
Cutting in
What should be done when preparing a hot water boiler for cutting in?
Fill the boiler and raise the pressure to at least the minimum required static pressure
What is the importance of maintaining an ample air cushion in the expansion tank during the warm-up period?
To accommodate the expanded water produced during warm-up
When should the boiler stop valve be opened during the independent warm-up procedure?
When the boiler reaches its operating pressure
What is the purpose of opening the boiler drum vent during the warm-up procedure?
To release corrosive dissolved gases from the boiler water
What should be done to the main steam shutoff valve during the simultaneous warm-up procedure?
It should be opened
What is the purpose of the boiler control switch during the warm-up procedure?
To turn the boiler on and off
What should be done to the boiler firing rate during the initial warm-up period?
It should be maintained at low fire
What should be done to the low point drains during the warm-up procedure?
They should be pinched back if blowing excessive steam
When should the superheater vent be opened during the warm-up procedure?
When the boiler reaches its operating pressure
What is the purpose of the trap bypasses during the warm-up procedure?
To release condensate as it forms
What should be done to the boiler during the warm-up procedure to prevent thermal shock and uneven expansion?
It should be operated at low fire
What should be done to the steam traps during the warm-up procedure?
They should be bypassed
During boiler startup, what is the primary reason for operators to shut down the boiler immediately if abnormal conditions occur?
To identify and correct the cause of the trouble
What is a common condition encountered during the warm-up period of a cold oil-fired boiler?
Slight smoking
Why is it essential for operators to closely monitor the boiler warm-up rates?
To prevent thermal shock
What should operators do before restarting a boiler after an abnormal condition has occurred during startup?
Identify and correct the cause of the trouble
What is the consequence of not paying attention to boiler warm-up rates during startup?
Leaks and premature boiler failure
What is the purpose of the ASME VI Recommended Rules for the Care and Operation of Heating Boilers in relation to boiler startup?
To ensure the safety and long life of boilers during startup
What is the primary reason for condensation in firetube boilers during startup?
Large water content in the boiler
What is the consequence of uneven expansion in a cold firetube boiler?
All of the above
Why does the furnace tube temperature rise faster than the firetube temperature in a steam boiler during startup?
Because the heat is not readily carried off by the water
What is the effect of scale buildup on the furnace and firetubes during startup?
It interferes with heat transfer and increases metal temperatures
What is the recommended action if smoking persists after the boiler is warmed up?
Take the burner out of service and clean the nozzle
What is the consequence of rapid heating of a cold firetube boiler?
Thermal shock and refractory damage
Why is it important to avoid high firing rates during the startup of a cold firetube boiler?
To prevent thermal shock and refractory damage
What is the purpose of ensuring the atomizing air or atomizing steam is at the correct pressure during startup?
To prevent smoking and ensure complete combustion
What is the result of thermal shock in a boiler?
Irregular expansion and contraction, causing internal stress
Why is it important to contact a qualified technician to adjust the air-fuel ratio if smoking persists after the boiler is warmed up?
To ensure complete combustion and prevent smoking
What is the primary purpose of reviewing the manufacturer's recommendations for burner and boiler startup?
To ensure the boiler is started in the safest manner possible
What is the purpose of the 5-minute purge period in a gas-fired atmospheric burner?
To ensure the combustion chamber is free of any combustible gases
What is the recommended course of action if the pilot flame is not established during the startup process?
Check the pilot ignition system for faults
What is the primary cause of the formation of tiny cracks in the metal of boiler tubes and tubesheets during startup?
Thermal shock
What is the purpose of the ASME VI Recommended Rules for the Care and Operation of Heating Boilers?
To provide guidelines for the operation and maintenance of boilers
What is the recommended rate of boiler water temperature increase to prevent thermal shock and allow for gradual thermal expansion?
55°C per hour
What is the likely consequence of introducing cold water into a hot boiler?
Thermal shock
What is the recommended approach to starting a cold hot water boiler?
Start the boiler at a low firing rate and gradually increase it
Why is it important to monitor the boiler during the warm-up and pressurizing period?
To prevent thermal shock and uneven expansion
What is the purpose of the boiler control switch during the startup process?
To control the ignition sequence of the boiler
What is the purpose of the air damper in a power burner system?
To control the flow of air to the boiler
What is the purpose of warming up a boiler slowly?
To prevent thermal shock and uneven expansion
What is the effect of scale buildup on the furnace and firetubes?
It reduces the boiler's efficiency
What is the recommended time to switch a boiler from low-fire to high-fire or automatic?
After the boiler has reached its normal operating pressure
What is the recommended approach to warm up the steam lines and headers in a single boiler steam plant?
Warm up the boiler first, then the steam lines and headers
What is the purpose of checking the furnace draft pressures during boiler startup?
To ensure the combustion gases are passing normally through the furnace and flue gas passages
What is the consequence of rapid temperature changes in a cold boiler during startup?
Formation of tiny cracks in the metal
What is the purpose of the log book in the boiler operation?
To record any abnormalities or issues encountered during the operation of the boiler
What is the purpose of bypassing part of the flow of cool return water around a warm boiler in a hot water heating system?
To prevent thermal shock and uneven expansion
What is the recommended firing rate control during the warm-up period?
Low firing rate
What is the primary reason for performing the operating and safety limit checks while the boiler is warming up?
To identify any potential safety hazards and take corrective action
What is the consequence of not warming up a boiler on low fire?
Uneven expansion and metal stress
What is the purpose of checking the water pressure on the tridicator gauge during the warm-up period?
To confirm the heating system is full and under pressure
Why is it necessary to close the valve in the connecting line between the boiler and the common expansion tank during the warm-up period?
To allow the pressure to equalize between the boiler and the expansion tank
What is the recommended approach to warming up the boiler when preparing it for cutting in?
Follow the same procedures as for a cold startup
What is the consequence of not checking the boiler frequently for leaks during the warm-up period?
Increased risk of boiler damage or failure
What is the purpose of the try lever and pop tests on the safety relief valve?
To confirm the safety relief valve is functioning properly
What is the recommended firing rate control when the boiler is warming up?
Low fire to prevent thermal shock and uneven expansion
What is the purpose of ensuring the boiler stop valves are closed during the warm-up period?
To prevent thermal shock and uneven expansion
What is the consequence of not maintaining an ample air cushion in the expansion tank during the warm-up period?
Insufficient space to accommodate expanded water
What is the primary reason for ensuring the boiler control switch is in the 'off' position before starting the warm-up procedure?
To allow the release of corrosive dissolved gases from the boiler water
What should be done to the main steam shutoff valve after the boiler reaches its operating pressure?
It should be fully opened
Why is it important to check the low point system drains during the warm-up procedure?
To release condensate as it forms
What should be done to the boiler firing rate during the initial warm-up period?
It should be placed on low fire
What should be done to the trap bypasses during the warm-up procedure?
They should be opened
What should be done to the superheater vent during the initial warm-up period?
It should be opened
Why is it important to ensure the boiler is steaming before increasing the firing rate?
To ensure good water circulation
What should be done to the steam traps during the warm-up procedure?
They should be bypassed
What should be done to the boiler drum vent valve after the boiler reaches its operating pressure?
It should be fully closed
Why is it important to maintain a low fire during the initial warm-up period?
To prevent thermal shock
What is the primary consideration when warming up a steam boiler and its steam piping system simultaneously?
To prevent water hammer and its associated damage
Why is it essential to warm up the steam header and main in a single boiler steam heating system?
To prevent water hammer and its associated damage
What is the recommended approach to starting a cold boiler in a single boiler steam heating system?
To warm up the boiler and its steam piping system simultaneously
What is the purpose of the low point drains, steam traps, and steam trap bypass lines during the warm-up period?
To remove condensate from the steam piping system
What is the advantage of warming up a steam boiler and its steam piping system simultaneously?
It prevents water hammer and its associated damage
Why is it important to warm up the steam piping system in a single boiler steam heating system?
To prevent water hammer and its associated damage
What is the recommended valve configuration when warming up a steam header or main in a single boiler steam heating system?
The boiler stop, header stop, and drain valves should be open
What is the purpose of the simultaneous warm-up procedure in a single boiler steam heating system?
To prevent water hammer and its associated damage
What is the result of warming up a steam boiler and its steam piping system simultaneously?
The steam piping system is warm and dry before the boiler is placed in service
What is the benefit of warming up the boiler and its steam piping system simultaneously in a single boiler steam heating system?
It prevents water hammer and its associated damage
What is the purpose of having multiple boilers in a larger steam system?
To provide additional capacity on standby when needed
What is the purpose of steam headers in multiple boiler systems?
To conduct steam from the boilers to other equipment in the plant
What is the consequence of not properly warming up and pressurizing steam headers and pipes?
Severe water hammer and potential piping damage
Why are multiple headers used in larger and more complex high-pressure steam plants?
To separate different pressure ranges and their corresponding equipment
What is the purpose of letting down steam from one header to another in a multiple header system?
To transfer steam from one header to another with a lower pressure
What is a key consideration when warming up steam headers and pipes in a multiple boiler system?
Removing condensate as it forms
Who should be in control during the manual operation of cutting in additional boilers?
A competent Power Engineer
What is the primary purpose of opening the drain valve between the stop valve at the boiler outlet and the steam main?
To discharge condensate as the steam lines warm up
In a multiple boiler plant, what is the procedure when all boilers have been shut down and the boiler being started up is the first to go on line?
Treat it exactly like the warm-up procedure for a single steam boiler plant
What is the purpose of the double block and bleed arrangement in a multiple power boiler plant?
To protect workers inside boiler drums when the connected header is energized
When placing a steam heating boiler on line with other heating boilers that are already in service, what should be done first?
Start the boiler using the procedure in Objective 3
What is the consequence of cutting in a steam boiler to a cold header?
Water hammer may occur
What is the purpose of warming up the steam lines and headers in a multiple boiler plant?
To prevent water hammer in the steam lines
When warming up a steam boiler and its steam piping system simultaneously, what is the primary consideration?
Preventing water hammer in the steam lines
What is the purpose of the non-return valve in a steam heating system?
To prevent condensate from accumulating above the non-return valve
When warming up a steam heating boiler, what should be done with the boiler supply stop valve and the return stop valve?
Close the boiler supply stop valve and the return stop valve
What is the primary purpose of restricting the opening of the non-return valve during the cut-in procedure?
To prevent flow surges and pressure upsets
In a semi-automatic burner ignition system, what is the purpose of the pre-purge step?
To remove any combustible gases from the boiler
What is the difference between a fully automatic and semi-automatic burner ignition system?
The level of operator interaction required
When cutting in a boiler without a non-return valve, what should be done when the boiler pressure is approximately equal to the header pressure?
Slowly open the boiler stop valve
What is the purpose of the post-purge step in a semi-automatic burner ignition system?
To remove any combustible gases from the boiler after ignition
When should the boiler non-return valve be fully opened?
When the boiler is supplying steam
What is the purpose of the pilot ignition step in a semi-automatic burner ignition system?
To establish a stable flame for the main burner
In a semi-automatic burner ignition system, what is the purpose of the main burner ignition step?
To light the main burner after the pilot has been established
Why is it important to have trained operators involved in the ignition sequence of a semi-automatic burner ignition system?
To manually control the ignition sequence
What is the purpose of the header stop valve bypass in a boiler cut-in procedure?
To equalize the pressure between the boiler and header
When warming up a steam line to the header using the steam from the boiler, what valve should be opened about 25%?
Non-return valve
Why are bypass valves used in the warming up process?
To prevent wire drawing
When should the drains be closed during the warming up process?
When the boiler is fully up to pressure and temperature
What is the purpose of slowly opening the header block valve bypass valve during the warming up process?
To warm up the steam line to the boiler
When can the boiler be cut-in to the pressurized steam header?
When the boiler is fully up to pressure and temperature
What is the purpose of keeping the boiler header block valve closed during the warming up process?
To prevent steam from entering the boiler
Why is it important to permit the drains to blow until the header and interconnecting piping are fully up to pressure and temperature?
To remove condensate from the steam lines
What is the purpose of comparing the pressure on the main steam header to the pressure of the steam line to the boiler?
To determine if the boiler is fully up to pressure and temperature
When should the main header steam block valve be slowly opened during the warming up process?
When the pressures in the main steam header and the steam line to the boiler are equal
What is the purpose of closing the header stop valve drain during the warming up process?
To ensure any condensate accumulating above the non-return valve is removed
What is the function of the proof of closure switch in the SSOV valve?
To prevent the ignition sequence from beginning if the valve fails to close
What is the purpose of the safety vent valve or 'bleed' solenoid in the fuel train?
To prevent gas from entering the furnace when the boiler burner is off
What is the function of the local burner control panel?
To start and stop the forced draft fan, and monitor the boiler status
What is required to be satisfied before the ignition sequence can begin?
All the boiler permissives, including water level, boiler pressure, and fuel pressure
What is the purpose of the main test firing valve proof of closure pre-ignition interlock switch?
To prevent the boiler from recycling or pre-purging
What happens when the burner is operating?
Valves L and N are both open, and vent M is closed
What is the purpose of the boiler master pressure set point?
To send control signals to the airflow and fuel flow controllers
What is required to start the burner?
Starting the forced draft fan, and pressing the PURGE START button after all permissives are satisfied
What is the purpose of the semi-automatic magnetic latching SSOV?
To manually open the main gas line, and automatically close it
What is the purpose of the local burner control panel status lights?
To show the status of the boiler, including when the purge is permissive, complete, and when the burner is ready to start
What is the purpose of the pre-purge period in the boiler startup sequence?
To exchange at least four furnace volumes of air
What should happen when the forced draft fan returns to its minimum airflow setting?
The BURNER READY light will come on
What should the operating pressure of a hot water boiler be in relation to the safety relief valve setting?
25% or 69 kPa (10 psi) less than the safety relief valve setting
What is the recommended maximum operating temperature for hot water boiler water?
120°C
What is a recommended operating pressure for steam heating boilers?
35 kPa (5 psi)
What is the purpose of the PILOT ON light?
To indicate that the pilot flame is stable
What should the movable hand on the tridicator gauge read in relation to the stationary hand?
At least 1.2m (11.8 kPa) greater than the stationary hand
What should happen when SSOV 'N' is of the magnetic latching valve style?
It must be reset by rotating the operating lever to the CLOSED position and then back to the OPEN position
Why should the boiler pressure set point not exceed 70 kPa (10 psi)?
To prevent weeping and protect the safety valve
What should the operator do with the main burner test firing valve during the ignition sequence?
Open it gradually to allow the burner to light gently
What is the purpose of the high steam pressure cut-off in power boilers?
To prevent the boiler pressure from exceeding the maximum allowable working pressure
What may occur if the expansion tank bladder has failed or the tank is full of water?
The safety valve will open
What should be checked during the post startup inspection of the boiler?
Routine instrument checks, heating system checks, and auxiliary system checks
What should be monitored during the warm-up period of a steam boiler?
All of the above
What is the purpose of monitoring the stack temperature?
To determine when waterside or fireside surfaces require cleaning
What should the boiler operator check periodically to prevent overheating?
The water level in the boiler
What should the boiler flame look like during normal operation?
Blue with orange tips (for natural gas) or bright yellow with orange tips (for light fuel oil)
What may indicate heat transfer surfaces are becoming dirty in a steam boiler?
Rising stack temperature at a given firing rate
What is the purpose of periodically walking down the fuel train line of a steam boiler?
To confirm there are no fuel leaks
What should be checked during the fuel train inspection?
Fuel leaks, pressure gauges, and downstream of the pressure regulators
What should the boiler operator check to ensure the heating needs of the system are being met?
The water temperature
What should the operator do if the boiler undergoes safety shutdown and lockout during the ignition sequence?
Reset the burner and restart the ignition sequence from the beginning
What is the purpose of the aqua-stat in hot water heating systems?
To cut off the burners once the temperature set point is reached
What should the boiler operator check for during the post-startup inspection of a steam boiler?
The water level in the boiler
Why is it important to check the circulating pump operation during the post startup inspection?
To ensure the pump is running quietly and without vibration
What is a typical characteristic of a natural gas flame?
It is blue with orange at the tip
What is the primary purpose of having multiple boilers in a steam system?
To provide additional capacity on standby
What is the consequence of not properly warming up steam headers and piping?
Severe water hammer and potential loss of life
What is the purpose of 'letting down' steam from one header to another in a multiple header system?
To connect the headers in sequence and provide steam to different equipment
What is the characteristic of steam headers in larger and more complex high-pressure steam plants?
They are identified by the pressures at which they operate
What is the benefit of having multiple boilers in a steam system during startup?
It allows the boiler being brought online to fire from cold
What is the complexity of header warm-up procedures in a multiple boiler or multiple header plant?
Very complex
When warming up a steam line to the header using steam from the boiler, what should be done to the boiler non-return valve?
Open it about 25%
What is the purpose of the bypass valves on the header block valves in a multiple boiler system?
To permit finer adjustment of the warm-up rate for the steam piping
When cutting in a boiler to a pressurized steam header, what should be done to the drains?
Permit them to blow until the header and interconnecting piping are fully up to pressure and temperature
What is the primary consideration when warming up steam headers and pipes in a multiple boiler system?
Preventing thermal shock to the pipes and headers
When using header steam to warm up the steam line to a boiler, what should be done to the header block valve bypass valve?
Open it slowly
What should be done to the boiler non-return valve drain when warming up the steam line to the header using steam from the boiler?
Open it fully
When cutting in a boiler to a pressurized steam header, what should be done to the boiler firing rate?
Operate in manual low-fire mode
What is the purpose of the drains located at the non-return valves and at the header block valves in a multiple boiler system?
To permit condensate to discharge from the system
When warming up a steam line to the header using steam from the header, what should be done to the header block valve?
Open it slowly
What is the primary consideration when connecting a new boiler to a pressurized steam header?
Preventing thermal shock to the pipes and headers
What is the primary purpose of opening the drain valve between the stop valve at the boiler outlet and the steam main when placing a steam heating boiler on line with other heating boilers that are already in service?
To drain condensate that accumulates above the non-return valve
When warming up a steam boiler and its steam piping system simultaneously in a single boiler steam heating system, what is the primary consideration?
Preventing uneven expansion in the boiler and steam piping
What is the purpose of the double block and bleed arrangement in a multiple power boiler plant?
To protect workers inside boiler drums when the connected header is energized
When should the header stop valve for Boiler A be slightly opened during the warm-up procedure in a multiple boiler plant?
When the boiler pressure is approximately the same as the pressure in the steam main
What is the consequence of not opening the drain valves at all system low points during the warm-up procedure in a multiple boiler plant?
Water hammer in the steam lines
Who should be in control during the manual operation of cutting in additional boilers?
A competent Power Engineer
When cutting in a boiler using Method One, what is the primary purpose of initially restricting the opening of the non-return valve?
To avoid flow surges and pressure upsets caused by sticking valves
What is the purpose of the drain valve on the Boiler A non-return valve during the warm-up procedure in a multiple boiler plant?
To drain condensate that accumulates above the non-return valve
In a semi-automatic burner ignition system, what is the primary purpose of the supervised main test firing valve?
To manually control the ignition sequence
When cutting in a boiler without a non-return valve, what is the primary purpose of equalizing the pressure between the boiler and header stop valves?
To ensure the header pressure equals the boiler steam line pressure
When should the boiler being started up be the first to go on line in a multiple boiler plant?
When all the boilers have been shut down
In a semi-automatic burner ignition system, what is the purpose of the pre-purge step?
To purge the fuel line of air
What is the benefit of warming up the boiler and its steam piping system simultaneously in a single boiler steam heating system?
It prevents thermal shock in the boiler and steam piping
When using Method Two to cut in a boiler, what is the primary purpose of shutting the Boiler 2 non-return drain valve?
To stop discharging condensate
What is the primary purpose of the header stop valve in a single power boiler plant?
To control the flow of steam from the boiler to the steam main
What is the primary purpose of the header stop valve bypass in Method Two?
To equalize the pressure between the boiler and header
In a semi-automatic burner ignition system, what is the primary purpose of the main test firing valve?
To manually control the ignition sequence
When cutting in a boiler without a non-return valve, what is the primary purpose of slowly opening the boiler steam stop valve?
To avoid flow surges and pressure upsets
In a semi-automatic burner ignition system, what is the primary purpose of the post-purge step?
To remove any remaining air or fuel from the system
When using Method One to cut in a boiler, what is the primary purpose of backing off on the stem of the non-return valve?
To automatically open the non-return valve
What is the purpose of the safety vent valve or 'bleed' solenoid in Figure 5?
To ensure no gas enters the furnace when the boiler burner is off
What is the function of the proof of closure switches on the main burner SSOVs?
To prevent the ignition sequence from beginning if the valve fails to close
What is required to be in the 'on' position before the ignition sequence can begin?
The boiler 'run' switch
What is the consequence if the valve fails to close completely due to mechanical failure or debris on the valve seats?
The proof of closure switch will not close
What is the purpose of the main test firing valve (Q) in Figure 5?
To prevent the ignition sequence from beginning unless the main test firing valve is in the fully closed position
What is the purpose of the local burner control panel status lights?
To indicate when the purge is permissive and complete
What is the sequence of events to start the burner?
Press the FD Fan START button, make sure the fan starts, and then press the PURGE START button
What is the purpose of the boiler master pressure set point in larger boilers?
To send control signals to the airflow controller and the fuel flow controller
What is the consequence if the boiler permissives are not satisfied before the ignition sequence can begin?
The ignition sequence will not begin
What is the purpose of valves L and N in Figure 5?
To automatically open and close the main gas line
What is the purpose of the pre-purge period in the boiler startup sequence?
To exchange at least four furnace volumes of air to remove any combustible gases
What happens when the purge is complete in the boiler startup sequence?
The PURGE COMPLETE light comes on
What is the purpose of the SSOV 'N' valve in the boiler ignition sequence?
To ensure a stable pilot flame is established
What should the operator do if the burner undergoes safety shutdown and lockout during the ignition sequence?
Restart the ignition sequence from the beginning
What is the recommended frequency for checking the circulating pumps in a hot water boiler system?
On a regular basis
What is the characteristic of a typical natural gas flame in a boiler?
Blue with orange tips
What is the purpose of checking the fuel train in a hot water boiler system?
To confirm there are no fuel leaks
What is the recommended approach to opening the supervised main test firing valve during the ignition sequence?
Open it gradually to allow the burner to light gently
What should the operator do during the post-startup inspection of the boiler?
Perform routine instrument checks, heating system checks, and auxiliary system checks
What is the consequence of not opening the supervised main test firing valve at the correct step in the ignition sequence?
The burner will undergo safety shutdown and lockout
What should be the normal steam heating boiler operating pressure relative to the safety valve setting?
35 kPa (5 psi) less than the safety valve setting
What is the purpose of the pressure differential between the boiler operating pressure and the safety valve setting in a steam heating boiler?
To ensure the safety valve will seat tightly after popping
What should be done during the periodic walk down of the fuel train line?
Check for fuel leaks and confirm fuel flow is sufficient to meet the load demand
In a power boiler, what is the purpose of the high steam pressure cut-off?
To prevent the boiler pressure from exceeding the boiler's maximum allowable working pressure
What may indicate that heat transfer surfaces are becoming dirty in a steam boiler?
Rising stack temperature at a given firing rate
What is the recommended recording during the observation of a boiler flame?
Both the burner pressure and firing rate
What is the recommended operating pressure for hot water heating boilers relative to the safety relief valve setting?
25% or 69 kPa (10 psi) less
What is the minimum recommended reading of the movable hand on the tridicator gauge relative to the stationary hand?
1.2m (11.8 kPa) greater
What is the maximum recommended temperature for hot water heating systems?
120°C
What is the recommended action to take when the expansion tank bladder has failed or is full of water?
Replace the expansion tank
What is the primary importance of maintaining the water level in a steam boiler?
To prevent overheating
What is the recommended frequency for alternating the boiler feed pumps?
Once a month
What is the characteristic of a light fuel oil flame?
Bright yellow with orange tips
What is the recommended action to take when the stack temperature is rising at a given firing rate?
Clean the heat transfer surfaces
What is the purpose of monitoring the water temperature in hot water heating systems?
To ensure the heating needs of the system are being met
What is the primary importance of checking the fuel oil pump suction and discharge pressures?
To ensure fuel flow is sufficient to meet the load demand
This quiz covers the importance of proper boiler warm-up rates, as recommended by manufacturers, to prevent leaks and premature failure. Learn about the effects of rapid heating on boiler metal and how to ensure safe startup conditions. Understand the abnormal conditions that may occur during light-off or warm-up periods.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
