54 Questions
EASY Why is it important to keep the boiler water pressure greater than atmospheric pressure during the layup period?
To prevent air from getting into the water
What is the primary purpose of coating the heating surfaces with mineral oil during the layup period?
To prevent corrosion
What is the recommended frequency for checking the boiler water?
Monthly
What is the purpose of capping a steam boiler with nitrogen?
To reduce the risk of corrosion
What is the typical pressure at which nitrogen is turned on to the steam space?
40 kPa
What happens to the nitrogen when the boiler is drained for annual maintenance?
It is left on
What is the purpose of thoroughly ventilating the boiler with fresh air prior to maintenance?
To ensure a safe working environment
What is the purpose of firing the boiler to remove dissolved gases?
To remove dissolved gases and circulate water treatment chemicals
Why is steam often used for capping boilers on hot standby?
Because it allows for faster return to operating pressure
What is the importance of maintaining the boiler water level in a steam-capped boiler?
To prevent condensed steam accumulation
What is the primary purpose of using the wet and dry layup methods for boiler storage?
To prevent corrosion
Which of the following boilers should preferably use the dry method of storage?
Boilers that will be out of service for extended periods of time
What is the purpose of placing trays with moisture absorbing materials in the boiler shell during the dry method of storage?
To absorb moisture from the air
Why should the wet layup method not be used for boilers that may be subjected to freezing temperatures?
Because it can cause damage to the boiler
What is the purpose of coating the fireside of heating surfaces with mineral oil during the dry method of storage?
To prevent corrosion
What should be done to the boiler after it is shut down and drained during the dry method of storage?
Clean the boiler fireside and waterside
Why is the wet layup method particularly useful for boilers that are required for service at short notice?
Because it allows the boiler to be quickly returned to service
What should be done to the boiler's connections during the dry method of storage?
Install blank flanges or blinds to prevent moisture entry
MEDIUM What is the primary purpose of the dry method of storage?
To prevent waterside corrosion during extended periods of inactivity
What should be used to fill the boiler during the wet layup method?
Deaerated water with chemicals
Why is the wet layup method not suitable for boilers that may be subjected to freezing temperatures?
Because it may cause the water to freeze and damage the boiler
What is the purpose of inspecting and renewing the moisture-absorbing material during the dry method of storage?
To prevent corrosion by absorbing moisture
What should be done to the boiler connections during the dry method of storage?
They should be closed with blank flanges or blinds
What is the purpose of coating the fireside of heating surfaces with mineral oil during the dry method of storage?
To prevent corrosion
Why is the dry method of storage preferable for boilers that will be out of service for extended periods of time?
Because it prevents corrosion
What is the primary benefit of using the wet layup method?
It allows for quicker startup
What is the primary reason for using a head tank to maintain pressure during the layup period?
To prevent air from entering the boiler water
What is the purpose of checking the boiler water at least monthly?
To ensure the correct chemical strength
What is the primary benefit of using nitrogen capping?
To prevent corrosion of the boiler surfaces
What happens to the nitrogen when the boiler is drained for annual maintenance?
It continues to fill the waterside spaces
Why is steam capping often used for boilers on hot standby?
To allow the boiler to be brought back to normal operating pressure quickly
What is the purpose of draining the boiler on occasion during steam capping?
To remove condensed steam from the drum
Why is it important to thoroughly ventilate the boiler with fresh air prior to maintenance?
To ensure the boiler is safe for maintenance
What is the purpose of firing the boiler after maintenance?
To remove dissolved gases from the boiler water
What is the primary benefit of using a heat exchanger in the mud drum during steam capping?
To heat the boiler water and maintain circulation
Why is it important to maintain the boiler water level in a steam-capped boiler?
To prevent condensed steam from accumulating in the drum
HARD What is the primary benefit of using the dry method of storage for boilers that will be out of service for extended periods of time?
Prevents waterside corrosion
Why is the wet layup method not suitable for boilers that may be subjected to freezing temperatures?
It may cause the water to freeze and damage the boiler
What is the purpose of using deaerated water in the wet layup method?
To reduce the risk of corrosion
What is the primary purpose of coating the fireside of heating surfaces with mineral oil during the dry method of storage?
To protect the surfaces from corrosion
Why is it important to inspect and renew the moisture-absorbing material during the dry method of storage?
To ensure the material continues to absorb moisture
What is the primary benefit of using the wet layup method for boilers that are required for service at short notice?
Allows for quicker restarting of the boiler
What is the purpose of closing the manhole and handhole doors during the dry method of storage?
To prevent moisture from entering the boiler
Why is it important to clean the boiler fireside and waterside during the wet layup method?
To reduce the risk of corrosion
What is the primary concern with using wet layup for boilers that may be subjected to freezing temperatures?
Formation of ice in the boiler water
What is the purpose of using a heat exchanger in the mud drum during steam capping?
To maintain water circulation during layup
What is the primary advantage of using nitrogen capping over steam capping?
Nitrogen is a more inert gas than steam
Why is it important to maintain the boiler water level in a steam-capped boiler?
To prevent accumulation of condensed steam
What is the primary purpose of firing the boiler after maintenance?
To remove dissolved gases from the boiler water
What is the primary benefit of using the wet layup method for boiler storage?
Faster startup time for the boiler
Why is it important to thoroughly ventilate the boiler with fresh air prior to maintenance?
To ensure safe entry into the boiler for maintenance
What is the primary purpose of using a head tank to maintain pressure during the layup period?
To prevent air from entering the boiler water
What is the primary reason for checking the boiler water at least monthly?
To ensure the correct strength of the water treatment chemicals
What is the primary benefit of using steam capping for boilers on hot standby?
Faster startup time for the boiler
Study Notes
Boiler Protection Against Corrosion
- Boilers must be protected against corrosion when out of service for a long time.
- Two methods are used to prevent waterside corrosion: wet and dry layup methods.
Dry Layup Method
- Preferable for boilers that will be out of service for extended periods or in locations with freezing temperatures.
- Procedure:
- Clean the boiler thoroughly.
- Inspect and make necessary repairs.
- Dry the boiler completely.
- Place trays with moisture-absorbing materials in the shell.
- Close manhole and handhole doors, and install blank flanges or blinds in all connections.
- Coat fireside with mineral oil.
- Close dampers and keep the furnace dry.
- Inspect and renew moisture-absorbing material at regular intervals.
Wet Layup Method
- Used for boilers that need to be in a standby condition and can be required for service at short notice.
- Not suitable for boilers that may be subjected to freezing temperatures.
- Procedure:
- Cool, drain, and lock out the boiler.
- Clean the boiler fireside and waterside.
- Fill the boiler with deaerated water, conditioned chemically to minimize corrosion.
- Maintain pressure greater than atmospheric pressure to prevent air from entering the water.
- Coat fireside with mineral oil.
- Check the boiler water monthly and maintain chemicals at the correct strength.
Capping Steam Boilers
- Wet layup exposes boilers to corrosion, especially if the boiler water is untreated and contains dissolved gases.
- Capping with inert gas or steam can be used to prevent corrosion.
- Common inert gas used is nitrogen.
Nitrogen Capping
- Uses nitrogen from compressed gas cylinders to fill the steam space.
- Procedure:
- Extinguish boiler fires and shut the steam outlet.
- Cool the boiler to around 40 kPa and turn on nitrogen.
- When the boiler is drained for maintenance, nitrogen is left on to prevent oxygen from reaching metal surfaces.
- Prior to maintenance, turn off nitrogen and thoroughly ventilate the boiler with fresh air.
Steam Capping
- Used for boilers on hot standby, laid up for short periods of time.
- Steam pressure prevents oxygen from entering the steam space during wet layup.
- Procedure:
- Use steam from a live steam header or a small steam heating boiler.
- Steam pressurizes the steam space and heats the boiler water.
- Pay attention to the boiler water level and drain the boiler occasionally to remove condensed steam.
Boiler Protection Against Corrosion
- Boilers must be protected against corrosion when out of service for a long time.
- Two methods are used to prevent waterside corrosion: wet and dry layup methods.
Dry Layup Method
- Preferable for boilers that will be out of service for extended periods or in locations with freezing temperatures.
- Procedure:
- Clean the boiler thoroughly.
- Inspect and make necessary repairs.
- Dry the boiler completely.
- Place trays with moisture-absorbing materials in the shell.
- Close manhole and handhole doors, and install blank flanges or blinds in all connections.
- Coat fireside with mineral oil.
- Close dampers and keep the furnace dry.
- Inspect and renew moisture-absorbing material at regular intervals.
Wet Layup Method
- Used for boilers that need to be in a standby condition and can be required for service at short notice.
- Not suitable for boilers that may be subjected to freezing temperatures.
- Procedure:
- Cool, drain, and lock out the boiler.
- Clean the boiler fireside and waterside.
- Fill the boiler with deaerated water, conditioned chemically to minimize corrosion.
- Maintain pressure greater than atmospheric pressure to prevent air from entering the water.
- Coat fireside with mineral oil.
- Check the boiler water monthly and maintain chemicals at the correct strength.
Capping Steam Boilers
- Wet layup exposes boilers to corrosion, especially if the boiler water is untreated and contains dissolved gases.
- Capping with inert gas or steam can be used to prevent corrosion.
- Common inert gas used is nitrogen.
Nitrogen Capping
- Uses nitrogen from compressed gas cylinders to fill the steam space.
- Procedure:
- Extinguish boiler fires and shut the steam outlet.
- Cool the boiler to around 40 kPa and turn on nitrogen.
- When the boiler is drained for maintenance, nitrogen is left on to prevent oxygen from reaching metal surfaces.
- Prior to maintenance, turn off nitrogen and thoroughly ventilate the boiler with fresh air.
Steam Capping
- Used for boilers on hot standby, laid up for short periods of time.
- Steam pressure prevents oxygen from entering the steam space during wet layup.
- Procedure:
- Use steam from a live steam header or a small steam heating boiler.
- Steam pressurizes the steam space and heats the boiler water.
- Pay attention to the boiler water level and drain the boiler occasionally to remove condensed steam.
Boiler Protection Against Corrosion
- Boilers must be protected against corrosion when out of service for a long time.
- Two methods are used to prevent waterside corrosion: wet and dry layup methods.
Dry Layup Method
- Preferable for boilers that will be out of service for extended periods or in locations with freezing temperatures.
- Procedure:
- Clean the boiler thoroughly.
- Inspect and make necessary repairs.
- Dry the boiler completely.
- Place trays with moisture-absorbing materials in the shell.
- Close manhole and handhole doors, and install blank flanges or blinds in all connections.
- Coat fireside with mineral oil.
- Close dampers and keep the furnace dry.
- Inspect and renew moisture-absorbing material at regular intervals.
Wet Layup Method
- Used for boilers that need to be in a standby condition and can be required for service at short notice.
- Not suitable for boilers that may be subjected to freezing temperatures.
- Procedure:
- Cool, drain, and lock out the boiler.
- Clean the boiler fireside and waterside.
- Fill the boiler with deaerated water, conditioned chemically to minimize corrosion.
- Maintain pressure greater than atmospheric pressure to prevent air from entering the water.
- Coat fireside with mineral oil.
- Check the boiler water monthly and maintain chemicals at the correct strength.
Capping Steam Boilers
- Wet layup exposes boilers to corrosion, especially if the boiler water is untreated and contains dissolved gases.
- Capping with inert gas or steam can be used to prevent corrosion.
- Common inert gas used is nitrogen.
Nitrogen Capping
- Uses nitrogen from compressed gas cylinders to fill the steam space.
- Procedure:
- Extinguish boiler fires and shut the steam outlet.
- Cool the boiler to around 40 kPa and turn on nitrogen.
- When the boiler is drained for maintenance, nitrogen is left on to prevent oxygen from reaching metal surfaces.
- Prior to maintenance, turn off nitrogen and thoroughly ventilate the boiler with fresh air.
Steam Capping
- Used for boilers on hot standby, laid up for short periods of time.
- Steam pressure prevents oxygen from entering the steam space during wet layup.
- Procedure:
- Use steam from a live steam header or a small steam heating boiler.
- Steam pressurizes the steam space and heats the boiler water.
- Pay attention to the boiler water level and drain the boiler occasionally to remove condensed steam.
This quiz covers the procedures for placing a boiler out of service for an extended period, focusing on the dry method of storage to prevent corrosion.
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