112 Questions
What is a limitation of flexible tube and coil tube type watertube boilers?
They require more monitoring for proper water treatment.
Why are flexible tube and coil tube type watertube boilers safer than firetube boilers?
They contain very little potential energy stored in their water.
What is a benefit of cast iron sectional boilers?
They are more corrosion resistant than steel boilers.
What is an advantage of flexible tube and coil tube type watertube boilers compared to firetube boilers?
They are more compact and lighter.
Why are flexible tube and coil tube type watertube boilers a good choice for smaller heating plants?
They are more compact and lighter.
What is a characteristic of flexible tube and coil tube type watertube boilers?
They develop little thermally induced stress.
What is the primary advantage of the coil tube boiler's arrangement?
Increased heat transfer due to turbulent flow
What type of tubing is commonly used in steam boiler varieties?
Steel
What is a critical aspect of water treatment in coil tube boilers?
Preventing scale deposition
What is the typical material used in the construction of cast iron sectional boilers?
Cast iron
What is the purpose of the push nipples in cast iron sectional boilers?
To create a seal between the sections
In a coil tube boiler, what is the function of the pump?
To circulate water through the coil
What is the benefit of using copper tubing in coil tube boilers?
It has a higher heat transfer rate than steel
What is the typical configuration of the sections in a horizontal sectional cast iron boiler?
Stacked one above the other like pancakes
What is the purpose of the collector hood in a cast iron sectional boiler?
To guide the hot gases to the vent connector
What is the common application of coil tube boilers?
Hot water supply and heating systems
What is an advantage of cast iron sectional boilers?
They can be increased in capacity by installing more sections.
Why are industrial type watertube boilers seldom selected for low-pressure heating plants?
They are more expensive than cast iron or steel firetube boilers.
What is the purpose of the mud drum and steam drum in a bent tube watertube boiler?
To return cooler water and supply hot water
How do the furnace walls in a bent tube watertube boiler absorb heat?
By radiation from the fire
What is the purpose of the outer membrane walls in a bent tube watertube boiler?
To form a passageway for the flue gases
What is the advantage of the flexible watertube boiler design?
All of the above
Why are bent tube watertube boilers popular for use as heating boilers?
They are designed for low-pressure steam or hot water service
What is the purpose of the circulation pump in a hot water application?
To force the water through the boiler
What is the purpose of the insulated steel casing in a bent tube watertube boiler?
To enclose the boiler and reduce heat loss
What is the result of the combustion gases traveling between the inner and outer membrane walls in a bent tube watertube boiler?
They transfer heat to the walls by convection
What is the main purpose of the removable panels in the casing of cast iron boilers?
To provide access to the boiler sections and flue gas passageways
What is the primary method of increasing heat transfer in cast iron boiler sections?
Exposing as large a surface as possible to the hot gases
What is the purpose of the extended surfaces on the cast iron boiler sections?
To increase the heating surface area
What does the capital letter 'H' cast into the section indicate?
That the section is designed, manufactured, and inspected according to ASME BPVC Section IV
What is a characteristic of the front and rear sections of cast iron boilers?
They have cleanout plugs on the side facing the outside of the boiler
How do the hot gases travel through the horizontal sectional cast iron boilers?
In a zigzag pattern
Why do multiple boilers increase the thermal efficiency of the boiler plant?
Because they allow most boilers to operate at full capacity during most of the heating season
What is a disadvantage of using a single large boiler in a heating plant?
It operates at reduced load during most of the heating season
What is the effect of cycling on the efficiency of a multiple boiler plant?
It reduces the overall efficiency of the plant by 2%
What is the primary advantage of using multiple small boilers in a heating plant?
They improve the thermal efficiency of the boiler plant
What is an advantage of multiple heating boiler plants compared to a single boiler plant of equal total capacity?
Should one boiler fail, the other boilers will be able to carry the full load except during extremely cold weather
What is a characteristic of a modular heating boiler plant?
The water flow through all modules is continuous
What is the purpose of a step controller in a multiple boiler plant?
To sense the outdoor air temperature and hot water supply temperature
What is a key difference between high-pressure and low-pressure firetube boilers?
The design and code requirements
Why are firetube boilers not suitable for use in high-pressure steam service?
They are not designed to handle high pressures
What is a common feature of hot water firetube boilers?
They have an aquastat
What is a characteristic of Scotch boilers?
They are available in small capacities
What is a feature of Scotch boilers in hot water service?
They have a full-size hot water return and hot water supply connection
What is a type of firebox boiler?
A low-pressure heating boiler
What is the capacity range of firebox boilers?
150 kW to 7000 kW
What is the main advantage of firebox boilers compared to Scotch-type firetube boilers?
They are more compact and can fit through standard doorways
How do the hot gases travel in a vertical firetube boiler?
Upwards through the firetubes
What is the purpose of the baffles in a vertical firetube boiler?
To slow the flue gas and maximize contact time
What is the main difference between conventional hot water heating systems and in-floor radiant heat systems?
The size of the heat transfer surfaces
What is the benefit of using a condensing boiler in in-floor radiant heat systems?
It increases the efficiency of the boiler to over 95%
What is the function of the handholes in a firebox boiler?
To clean and inspect the waterside
What is the purpose of the flue gas collector box in a vertical firetube boiler?
To collect the hot gases for venting
Why are vertical firetube boilers less common in heating plants today?
They are not very efficient
What is the advantage of a vertical firetube boiler when floor space is limited?
It requires less floor space
What is the function of the circulating pump in a vertical firetube boiler?
To force the cooler water into the lower part of the boiler shell
What is a characteristic shared by flexible tube and coil tube type watertube boilers in terms of their size and weight?
They are considerably smaller and lighter than firetube boilers of equal capacity.
What is a requirement for the operation of flexible tube and coil tube type watertube boilers that is not necessary for firetube and cast iron sectional heating boilers?
Close monitoring of the water treatment.
What is an advantage of cast iron sectional boilers compared to steel boilers?
They are more corrosion resistant.
Why are flexible tube and coil tube type watertube boilers considered safer than firetube boilers?
They contain very little potential energy stored in their water.
What is a feature of flexible tube and coil tube type watertube boilers that makes them suitable for smaller heating applications?
They come as packaged units, complete with firing equipment, automatic controls, and safety devices.
What is an advantage of flexible tube and coil tube type watertube boilers in terms of their response to heating loads?
They respond rapidly to fluctuating heating loads.
What is the primary reason why copper tubing is used in coil tube boilers?
It resists corrosion and has a better heat transfer rate
What is the purpose of the fin-and-tube type heat exchanger in the upper section of the copper tubular heating boiler?
To increase the heating surface area
What is the characteristic of the combustion chamber in a coil tube boiler?
It is surrounded by a tightly wound coil
What is the purpose of the gaskets in a cast iron sectional boiler?
To seal the passageways between sections
What is the advantage of using multiple coil tube boilers in a heating plant?
Flexibility to meet varying heating demands
What is the primary difference between a vertical sectional cast iron boiler and a horizontal sectional cast iron boiler?
The arrangement of the sections
What is the purpose of the collector hood in a cast iron sectional boiler?
To guide the hot gases to the draft hood
What is the characteristic of the steam boiler varieties?
They use steel tubing
What is the critical aspect of water treatment in coil tube boilers?
Preventing scale deposition
What is the main advantage of using cast iron sectional boilers over installing more boilers?
They can be increased in capacity by installing more sections.
Why are industrial type watertube boilers seldom selected for low-pressure heating plants?
All of the above
What is the benefit of the compact design of the copper tubular heating boiler?
Reduced space requirements
What is the function of the furnace walls in a bent tube watertube boiler?
To absorb radiant heat from the fire.
What is the purpose of the outer membrane walls in a bent tube watertube boiler?
To form a passageway for the flue gases.
What is the benefit of the bent tube watertube boiler design?
It is more compact and can fit through a standard doorway.
How do the combustion gases travel in a bent tube watertube boiler?
Between the inner and outer membrane walls.
What is the purpose of the circulating pump in a hot water application?
To force the water through the boiler.
What is the advantage of the flexible watertube boiler design?
It allows the tube to expand and contract without creating excessive stress.
What is the purpose of the insulated steel casing in a bent tube watertube boiler?
To enclose the boiler and reduce heat loss.
What is the result of the combustion gases traveling between the inner and outer membrane walls in a bent tube watertube boiler?
They transfer heat to the walls by convection.
What is the primary reason for designing cast iron boiler sections with extended surfaces?
To expose as large a surface as possible to the hot gases
What is the advantage of specifying several small boilers in parallel, rather than a single large boiler, in a heating plant?
Increased efficiency during most of the heating season
What is the purpose of the push nipple connections in a cast iron boiler section?
To connect the sections to each other
What is the primary benefit of using multiple small boilers in a heating plant, compared to a single large boiler of equal total capacity?
Reduced risk of damage or injury due to smaller water capacity
What is the significance of the capital letter 'H' cast into the top of a cast iron boiler section?
It indicates the section is designed, manufactured, and inspected according to ASME BPVC Section IV
What is the main difference between high-pressure and low-pressure firetube boilers?
Design code, with high-pressure boilers designed to ASME BPVC Section I and low-pressure boilers designed to ASME BPVC Section IV
What is the effect of cycling on the overall efficiency of a multiple boiler plant?
It decreases the overall efficiency of the plant, but only by a small amount
What is the purpose of a step controller in a multiple boiler plant?
To sequence the startup and shutdown of boilers as load demand increases or decreases
What is the primary advantage of horizontal sectional cast iron boilers?
They are more compact than vertical sectional boilers
What is a characteristic of firebox boilers in hot water service?
They are designed to burn light fuel oil, natural gas, and propane
What is the purpose of the cleanout plugs in the front and rear sections of a cast iron boiler?
To clean out debris from the boiler sections
What is the primary reason for designing cast iron boiler sections with a zigzag pattern of gas passages?
To lengthen the time of contact between the hot gases and the heating surface
What is the advantage of using multiple boilers in a heating plant, compared to a single large boiler of equal total capacity?
Increased reliability and reduced downtime
What is the primary advantage of Scotch boilers in hot water service?
They have full-size hot water return and supply connections
What is the primary advantage of using multiple small boilers in a heating plant, compared to a single large boiler?
Smaller boilers can be operated at maximum efficiency more often
What is the effect of operating a single large boiler at reduced load on its efficiency?
It decreases the boiler's efficiency significantly
What is the purpose of the isolation valves in Scotch boilers in hot water service?
To permit servicing or repairing the boiler without draining the entire heating system
What is the advantage of a modular heating boiler plant?
It provides increased redundancy and reliability
What is the primary benefit of using low-pressure boilers in a heating plant?
They reduce the risk of damage or injury due to lower water pressure
What is the primary advantage of firetube boilers in hot water heating systems?
They are designed to operate at the lower temperatures required for hot water heating systems
What is the primary advantage of firebox boilers over Scotch-type firetube boilers?
They are more compact and can fit through standard doorways
What is the purpose of the baffles in a vertical firetube boiler?
To slow the flue gas and maximize contact time
Why are vertical firetube boilers less common in heating plants today?
They are less efficient than other boiler designs
What is the benefit of using a condensing boiler in in-floor radiant heat systems?
It allows for efficiencies of over 95%
What is the purpose of the handholes in a firebox boiler?
To clean the waterside
What is a characteristic of the hot water return and hot water supply connections in firebox boilers?
They are equipped with isolation valves
How do the hot gases travel in a vertical firetube boiler?
They travel upwards through the flue gas collector box
What is the primary advantage of using multiple small boilers in a heating plant?
It provides more flexibility in response to heating loads
What is the purpose of the manhole in a firebox boiler?
To clean and inspect the boiler
What is the main difference between conventional hot water heating systems and in-floor radiant heat systems?
The size of the heating surface area
This quiz covers the different types of boilers, including firetube and watertube boilers, and their applications in various heating plants. Learn about the advantages and disadvantages of flexible tube, coil tube, and cast iron sectional boilers. Discover which boiler type is suitable for specific heating needs.
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