39 Questions
EASY What is the recommended pH level for the water in the boiler during the layup period?
10
What is the purpose of adding sodium sulfite to the water in the boiler?
To provide a sufficient quantity of oxygen scavenger residual
What is the recommended pressure to maintain on the boiler during the layup period?
40 kPa
What is the purpose of filling the boiler until it overflows from the vents?
To remove air from the boiler
What is the final step in preparing the boiler for layup?
Maintain approximately 40 kPa of pressure on the boiler
What is the most common method used for long-term shutdown of steam boilers?
Dry layup
Why is a dry layup preferred in freezing conditions?
To prevent freezing of water inside the boiler
What is the purpose of using air movers in a dry layup?
To force air through the boiler and out the steam drum
How often should desiccant trays be checked in a dry layup?
Bi-weekly to monthly
What is the recommended quantity of quicklime for every 2.83 m3 of boiler volume?
3.2 kg
What is the purpose of adjusting boiler chemistry in a wet layup?
To account for long-term chemical needs
Why is it advisable to drain the boiler and clean its fireside and waterside prior to a wet layup?
To ensure the chemicals are thoroughly circulated
Which type of layup is common for shorter duration shutdowns?
Wet layup
MEDIUM What is the primary purpose of consulting a certified water treatment professional during the wet layup preparation?
To identify the necessary chemicals and their concentrations for the boiler water
What is the primary function of the sodium sulfite in the boiler water during the layup period?
To provide a sufficient quantity of oxygen scavenger residual
Why is it necessary to maintain 40 kPa of pressure on the boiler during the layup period?
To prevent corrosion of the boiler components
What is the purpose of filling the boiler until it overflows from the vents?
To remove any air pockets from the boiler
What is the purpose of shutting down the boiler before filling it with water?
To ensure the boiler is safe for the layup period
What determines the method of layup to be used on a steam boiler?
The expected duration and purpose of the layup
What is the primary purpose of using desiccant in a dry layup?
To absorb moisture
When is a wet layup typically used for a steam boiler?
For short-term shutdowns
What is the purpose of closing and making leak-tight all openings to and from the boiler in a dry layup?
To prevent moisture from entering the boiler
Why is it important to dry the boiler thoroughly in a dry layup?
To prevent corrosion
What is the purpose of adjusting boiler chemistry in a wet layup?
To account for long-term chemical needs
What is the recommended frequency for checking desiccant trays in a dry layup?
Bi-weekly to monthly
Why is it important to drain and clean the boiler prior to a wet layup?
To remove any debris or sediment
HARD What is the primary reason for using a dry layup instead of a wet layup in freezing conditions?
To prevent freezing of water in the boiler
What is the purpose of using air movers in a dry layup?
To force air through the boiler and out the steam drum
What is the purpose of placing trays of moisture-absorbing materials inside the boiler shell or drums?
To catch the removed moisture and maintain a dry environment
Why is it necessary to close and make leak-tight all openings to and from the boiler in a dry layup?
To prevent moisture from entering the boiler
What is the primary function of the desiccant in a dry layup?
To absorb moisture from the air
What determines the frequency of checking desiccant trays in a dry layup?
Bi-weekly to monthly basis
What is the primary purpose of adjusting boiler chemistry in a wet layup?
To account for long-term chemical needs
Why is it advisable to drain the boiler and clean its fireside and waterside prior to a wet layup?
To ensure the boiler is clean and free of debris
What is the primary reason for adjusting the pH of the water to 10 during the wet layup procedure?
To reduce the risk of corrosion within the boiler
What is the primary role of the head tank, nitrogen blanket, or steam blanket in the wet layup procedure?
To maintain a constant pressure on the boiler
Why is it necessary to fill the boiler until it overflows from the vents during the wet layup procedure?
To ensure the removal of air from the boiler
What is the primary benefit of consulting a certified water treatment professional during the wet layup procedure?
To develop a customized chemistry regimen for the boiler water
What is the primary purpose of depressurizing the boiler before filling it with water during the wet layup procedure?
To prevent the formation of steam pockets in the boiler
Study Notes
Proper Storage of Out-of-Service Steam Boilers
- Proper storage is critical for maintaining the longevity of a steam boiler
- Improper layup can shorten a boiler's lifespan
Dry Layup Method
- Used for long-term shutdown, boilers not on standby, shutdown in freezing conditions, and when internal inspection or boiler entry is required
- Steps:
- Shut down the boiler
- Lock out, drain, and clean the boiler
- Dry the boiler thoroughly using air movers
- Place trays of moisture-absorbing materials (quicklime, silica gel, or activated alumina) inside the shell or drums
- Quantities:
- 3.2 kg of quicklime for every 2.83 m3 of boiler volume
- 3.6 kg of silica gel for every 2.83 m3 of boiler volume
- Close and seal handholes, manholes, inspection ports, and all openings
- Check desiccant trays bi-weekly to monthly to assess replacement needs
Wet Layup Method
- Used for shorter duration shutdowns, boilers on standby, and shutdowns when freezing conditions cannot occur
- Steps:
- Adjust boiler chemistry for long-term chemical needs
- Add chemicals while the boiler is operating to ensure circulation
- Drain and clean the boiler (optional but advisable)
- Procedure for direct wet layup:
- Perform water tests as per plant procedures
- Adjust pH to 10 using recommended alkali
- Adjust sodium sulfite to 200 ppm for sufficient oxygen scavenger residual
- Adjust all other chemical parameters to recommended regimen
- Shut down and depressurize the boiler
- Fill the boiler until it overflows, then close vents
- Maintain 40 kPa pressure during the layup period
Proper Storage of Out-of-Service Steam Boilers
- Proper storage is critical for maintaining the longevity of a steam boiler
- Improper layup can shorten a boiler's lifespan
Dry Layup Method
- Used for long-term shutdown, boilers not on standby, shutdown in freezing conditions, and when internal inspection or boiler entry is required
- Steps:
- Shut down the boiler
- Lock out, drain, and clean the boiler
- Dry the boiler thoroughly using air movers
- Place trays of moisture-absorbing materials (quicklime, silica gel, or activated alumina) inside the shell or drums
- Quantities:
- 3.2 kg of quicklime for every 2.83 m3 of boiler volume
- 3.6 kg of silica gel for every 2.83 m3 of boiler volume
- Close and seal handholes, manholes, inspection ports, and all openings
- Check desiccant trays bi-weekly to monthly to assess replacement needs
Wet Layup Method
- Used for shorter duration shutdowns, boilers on standby, and shutdowns when freezing conditions cannot occur
- Steps:
- Adjust boiler chemistry for long-term chemical needs
- Add chemicals while the boiler is operating to ensure circulation
- Drain and clean the boiler (optional but advisable)
- Procedure for direct wet layup:
- Perform water tests as per plant procedures
- Adjust pH to 10 using recommended alkali
- Adjust sodium sulfite to 200 ppm for sufficient oxygen scavenger residual
- Adjust all other chemical parameters to recommended regimen
- Shut down and depressurize the boiler
- Fill the boiler until it overflows, then close vents
- Maintain 40 kPa pressure during the layup period
Proper Storage of Out-of-Service Steam Boilers
- Proper storage is critical for maintaining the longevity of a steam boiler
- Improper layup can shorten a boiler's lifespan
Dry Layup Method
- Used for long-term shutdown, boilers not on standby, shutdown in freezing conditions, and when internal inspection or boiler entry is required
- Steps:
- Shut down the boiler
- Lock out, drain, and clean the boiler
- Dry the boiler thoroughly using air movers
- Place trays of moisture-absorbing materials (quicklime, silica gel, or activated alumina) inside the shell or drums
- Quantities:
- 3.2 kg of quicklime for every 2.83 m3 of boiler volume
- 3.6 kg of silica gel for every 2.83 m3 of boiler volume
- Close and seal handholes, manholes, inspection ports, and all openings
- Check desiccant trays bi-weekly to monthly to assess replacement needs
Wet Layup Method
- Used for shorter duration shutdowns, boilers on standby, and shutdowns when freezing conditions cannot occur
- Steps:
- Adjust boiler chemistry for long-term chemical needs
- Add chemicals while the boiler is operating to ensure circulation
- Drain and clean the boiler (optional but advisable)
- Procedure for direct wet layup:
- Perform water tests as per plant procedures
- Adjust pH to 10 using recommended alkali
- Adjust sodium sulfite to 200 ppm for sufficient oxygen scavenger residual
- Adjust all other chemical parameters to recommended regimen
- Shut down and depressurize the boiler
- Fill the boiler until it overflows, then close vents
- Maintain 40 kPa pressure during the layup period
Learn about the importance of proper storage for steam boilers and the steps involved in the dry layup method for long-term shutdown.
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