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199 Cards in this Set
- Front
- Back
Even though the modern boiler is automated for easier operation, it requires what? |
Regular supervision and maintenance. |
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Define "Steam boiler" |
Closed container, partially filled with water. |
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Define "Hot water boiler" |
Closed container, completely filled with water. |
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What is the provincial legislation's definition of a boiler? |
A pressure vessel in which a gas or vapour can be generated under pressure, or liquid can be put under pressure via application of heat. |
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Define "Baffle" |
Directs the flue gas through the boiler. |
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What are "Blowdown valves" used for? |
Used to drain, or remove sediment from bottom of the boiler. (suspended solids) |
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"Blowdown valves" can take on various forms. Name 2 types. |
Slow opening, Quick opening. |
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Define "Boiler failure" |
Occurs when a ruptured or cracked tube allows high-pressure steam or water to escape. |
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Define "Combustion Chamber" |
Where air and fuel combine in a chain reaction to cause sustained burning. |
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Combustion gases are also known as: |
Flue gases. |
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Define "Combustion gas pass" |
The path the flue gases travel along the length of the boiler. |
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Define "Condensate" |
The water formed from the condensing steam. |
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What is another name for the "drum"? |
Shell. |
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Define "Externally fired boiler" |
A boiler with the combustion chamber outside of the shell or drum. |
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Define "Feedwater" |
Water that is fed into a steam boiler to replace the water which has been converted to steam. |
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In a "Firetube boiler", where does the flue gases travel? |
Through the tubes. |
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Define "fitting" |
Any valve, gauge, regulating device, flange, or various other attachments. |
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Define "Flame scanner" |
Used to monitor the boiler. Signals the fuel supply valves to close to prevent explosion. |
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Define "Forced Draft Fan" |
Supplies air to the furnace. |
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Define "Gauge Glass" |
Used to observe boiler water level. |
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What needs to be checked weekly on a Generally Supervised Boiler? |
Controls are working, boiler water is treated, boiler is working properly. |
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Define "Handhole" |
A small, hand sized inspection, cleaning and maintenance port. |
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Define "Header" |
A large pipe which supplies or collects from a series of smaller pipes or tubes. Also called a manifold. |
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Define "Heads" |
Steel plates, end plates. |
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If the shell contains tubes which are held in position by the heads, they are called: |
Tube sheets. |
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Define "Heating surface" |
Any surface with steam or water on one side, swept by hot flue gases on the other side. |
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At what pressure are boilers considered high-pressure?
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103 kPa. |
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What is another name for high-pressure boilers? |
Power boilers. |
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Important points regarding Hot water boilers are: |
Completely filled with water. No steam is generated. |
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Name 3 different types of Hot water boilers: |
Low-pressure hot water heating boilers. Hot water supply boilers (hot water tanks). High-temperature hot water boilers. (above 121 degrees) |
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According to ASME, Section VIII (8), hot water supply boilers (hot water tanks) are not considered heating boilers unless one or more of the following conditions are met: |
Capacity - 450 L Temperature - 99 degrees Energy input - 58.7 kW |
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Define "Induced draft fan" |
Draws flue gases out of the of the boiler. |
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Internally-fired boilers are: |
Furnace located within the shell or drum. |
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Lowest Permissible Water Level (LPWL) is: |
The lowest level which the boiler can be safely operated. |
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What is the LPWL for Heating boilers, Power boilers and HRT boilers? |
25mm. 50mm. 76mm. (Same order as question stated) |
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Low-pressure steam boilers do not operate above: |
103 kPa. |
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Low-Water Fuel Cutoff is what? |
A safety device which cuts off the fuel supply to the boiler if the water level drops below a safe level. |
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Define "Manhole" |
An opening or hatch through which a person may enter. |
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Pressure gauges are also known as: |
Steam gauges. |
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What is a rupture disk? |
A rupture disk is a safety device, it must be replaced when it activates. |
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What is a safety valve? |
A fitting that prevents the pressure within a steam boiler from exceeding safe limits. |
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What is a "setting"? |
A brick arrangement used in older type boilers. Found commonly in HRT type boilers. |
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Define "Steam space" |
Portion of the boiler not filled with water. |
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Define "Waterleg" |
A water-filled section which extends from the shell. Found in locomotive type boilers. |
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Define "Windbox" |
The box surrounding the burner damper on a boiler. FD blows air into the box and this regulates and directs the air into the burners. |
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In a boiler, what steam generating parts must be covered by water? |
All of them. |
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What does a "Steam gauge" indicate? |
Internal pressure of the boiler.
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What is the earliest form of steam boiler? |
Haycock boiler from 1720. |
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Why were these early types of boilers inefficient? |
The heating surface was small. |
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An efficient boiler should be designed to: |
Absorb maximum amount of heat. Provide maximum safety and reliability. Compactness to keep building costs down. Provide adequate access for maintenance. |
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What is the process name for thermo-flooding boilers which inject large amounts of heat energy into geological formations? |
Sag-D |
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An example of a boiler fitting would be a: |
Pressure gauge. |
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A watertube boiler is a boiler in which: |
Water passes through the tubes. |
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A _____ is a water-filled section, which surrounds the firebox in a locomotive boiler. |
Waterleg. |
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A device that normally uses air or steam to do its job is the: |
Sootblower. |
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When part of the firetube boiler itself, heads are commonly called: |
Tube Sheets. |
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The steam space of a boiler must be large enough to: |
Separate water from the steam. |
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A hot water boiler is considered a high temperature water boiler when: |
Design pressure is greater than 1100 OR temps exceed 121 degrees. |
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The windbox of a boiler is: |
What the FD fan is installed into. |
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A safety valve is a fitting that will prevent the boiler pressure from exceeding a set maximum by: |
Popping open and relieving all the pressure. |
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HRT stands for: |
Horizontal return tubular. |
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Firetube boilers consist of: |
Water-filled shell containing tubes through which flue gases travel. |
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Firetube boilers feature: |
Simple, rugged construction and low cost. |
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Downside to additional passes in a firetube boiler is: |
Slows flue gas velocity. |
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To maintain flue gas velocity, what must be done? |
Passes must have few tubes or fans may be added. |
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HRT Boilers are some of the _____ types of firetube boilers. |
Earliest. |
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Locomotive type boilers are _____ fired which has a capacity up to _____ kg/h at _____ kPa and are surrounded by _____ on four sides. |
1. Internally 2. 6800 3. 2400 4. Waterlegs |
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Where are Locomotive type boilers typically found? |
1. Heating plants 2. Small industrial plants 3. Oil field industry |
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A locomotive boiler, with waterleg that extends only down the sides is called _____. |
Dry Bottom. |
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A locomotive boiler, with a waterleg that encloses the bottom of the furnace is called a _____. |
Wet Bottom. |
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Downsides to the locomotive type boiler: |
1. A lot of staying. 2. Poor water circulation. 3. difficult to maintain. 4. Poor cleaning + inspection access. |
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The firebox boiler is an _____ fired boiler. |
Externally. |
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Firebox boilers are _____, _____ and _____. |
1. Compact 2. Efficient 3. Initially expensive. |
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Firebox boilers have similar downsides to the locomotive type, which are: |
1. Difficult to maintain 2. Poor cleaning + inspection. |
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Firebox sometimes utilise _____. |
Waterlegs. |
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Scotch Marine Boilers are the _____ of the modern package firetube boiler. |
Forerunner. |
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What do "dry pipes" do? |
Takes moisture out of the steam. |
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The Scotch Marine Boilers are horizontal and _____ fired. |
Internally.
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Scotch Marine Boilers that utilise a waterleg are commonly used in a _____. |
Marine service setting. |
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Scotch boilers incorporate what kind of furnace? |
Corrugated. |
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What is the benefit of a corrugated furnace? |
Allows for expansion and reduces stress. |
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ASME, Section IV (4), HG-101.1, identifies steam heating boilers as not exceeding _____ kPa and hot water heating boilers as not exceeding _____ degrees and _____ kPa. |
1. 100 2. 120 3. 1100 |
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Vertical firetube boilers are _____ pass. |
Single. |
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A common type of vertical heating boiler is the _____ boiler. |
Steel plate. |
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Lower part of these types of boilers is the: |
Combustion chamber or furnace. |
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Baffles are installed inside the tubes and are made out of: |
Thin steel strips. |
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This gives the gas a _____. |
Swirling motion. |
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A problem with early firetube boilers was: |
Too many people involved with the assembly. |
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Modern package firetube boilers are _____, _____ and _____ tested before shipment.
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1. Engineered 2. Built 3. Fire |
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Modern package firetube boilers come ready for _____. |
Installation. |
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Another upside to the modern package firetube boiler is it requires: |
Small building volumes. |
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5 advantages of a modern packaged firetube boiler: |
1. Lower freight cost. 2. Mass produced, lower initial cost. 3. Quality control. 4. Factory tested. 5. Req. little time to boiler into service. |
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Key advantage of a modern packaged firetube boiler: |
Mass produced, lower initial cost. |
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An advantage of a locomotive boiler over other boilers of the era was: |
Rugged construction. |
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An internally fired boiler: |
has a furnace surrounded by water. |
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A corrugated furnace gives required strength with thinner metal, increases heating surface and: |
Allows for differential expansion and contraction. |
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In regards to assembly and transportation of a packaged firetube boiler it comes: |
Supplied already mounted on a base. |
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Which one of the following is NOT an advantage of a packaged firetube boiler? (Hint: the reason why large plants use watertube boilers) |
Large enough to provide steam for large-scale power generation.
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An advantage of a vertical firetube boiler is that it requires: |
Relatively small floor space. |
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When a packaged firetube boiler is designed as a power boiler rather than a heating boiler: |
It will have a much stronger construction. |
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A vertical firetube boiler is divided into a lower section, called the furnace, and an upper section called the: |
Heat exchanger. |
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To maintain high velocities through all gas passes in a 4-pass firetube boiler, the cross-sectional area of each succeeding pass is: |
Decreased. |
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A reason for preferring copper tubing in a tubular boiler is: |
Corrosion resistance. |
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Immersion boiler tube bundles: |
Can be easily removed from the unit for maintenance purposes. |
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To prevent flue gas leakage from the furnace of a packaged watertube boiler: |
A steel casing forms a seal for the furnace. |
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Electric boilers don't require a: |
Chimney. |
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A packaged watertube boiler having two mud drums is the: |
"A" type. |
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The amount of current passed through the water of an electrode boiler depends on the: |
Depth of the electrodes in the water. |
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What safety device is not required on an electrode type boiler? |
Low water cut-off. |
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An initial problem with the tubular watertube boiler being used in steam service was: |
Dissolved impurities formed scale on the tube. |
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In order to keep the concentration of dissolved solids within safe limits, the packaged tubular steam boiler utilises an: |
Automatic blow down. |
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The use of bent tube boiler designs allows the furnace wall to be lined with tubes, thereby exposing more of the heating surface to: |
Radiant heat. |
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The steam produced by an electrode type boiler depends on the: |
Level of water in the basket. |
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An advantage of a packaged, low pressure tubular or watertube boiler is: |
Safety due to the low volume of water it contains. |
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The operating voltage for an electrode boiler may be as high _____ volts: |
16 000 volts. |
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Large steam generating units are designed to produce high pressure superheated steam for the purpose of: |
Generating electrical power using steam turbines. |
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One advantage of the low-pressure serpentine watertube boiler is that: |
Expansion and contraction stresses are eliminated. |
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Most electric boilers are limited in pressure to about 2100 kPa, due to the effect of high temperature on the: |
Elements or electrodes. |
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The copper tube tubular boiler can be either? |
Gas or oil fired. |
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The furnace walls in a bent-tube watertube boiler are formed by water filled tubes called: |
Waterwalls. |
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A reason for preferring copper tubing in a tubular boiler is: |
Greater heat transfer rate. |
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The purpose of a superheater is to: |
Increase the temperature of the steam. |
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A _____ boiler incorporates a basket and a basket drain valve. |
Electrode. |
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Air heaters are implemented in steam generating units in order to: |
Improve boiler thermal efficiency. |
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Watertube boilers are better suited to high pressure because: |
1. Bent tube design. 2. Does not have flat surfaces. 3. Smaller dia. tube. 4. Smaller dia. drums. |
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In a straight tube design (longitudinal), how is the water fed to the rear header? |
By means of a downcomer. |
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A cross drum straight tube boiler could have more _____ than a longitudinal type: |
Incline tubes. |
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What are the most common type of water tube boilers? |
"A", "D" and "O" |
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What is sometimes a problem with "A" type boilers? |
Excessive vibration and insulation loss. |
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What is sometimes a problem with "D" type boilers? |
Ceiling height requirements. |
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What is another name for the Four-Drum Bent Tube Boiler? |
Sterling. (Department of Labour question) |
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On a packaged watertube boiler may contain _____ _____ in front of the watertube walls due to the _____ _____ of the _____. |
Steel sheeting, erosive action of the flame. |
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Another downside to the packaged watertube boiler are: (Hint: transportation) |
transportation requirements limit the height of the boiler. |
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Steam generating units would not utilise a _____. |
Cyclone furnace. |
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What is the most economical fuel to use in a steam generated unit? |
Pulverised coal. |
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Where are convection superheater tubes located? |
Away from the fire. |
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What does the economiser do? |
Increases boiler efficiency. |
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Where is the economiser located? |
between the air heater and primary superheater. |
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What do air heaters do? |
recover heat from the flue gas and improve boiler efficiency. |
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Why do we build large generating units? |
So large steam turbines can be used to drive electrical generators. |
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Low pressure heating boilers operate below 103 kPa and 121 degrees. But in some jurisdictions/provinces its: |
100 kPa and 120 degrees. |
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What's another benefit to the low pressure, serpentine type watertube boiler? |
Threaded stock so tubes can be replaced. |
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Tubular steam heating boilers are used in conjunction with _____ _____ to keep salt concentrations down. |
Automatic blowdown. |
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Why is softened water used as feedwater? |
to prevent scale from forming. |
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What are some advantages of the low pressure watertube and tubular type boilers? |
1. Bent or coil design avoids thermal stress and distortion. 2. Safer than firetube boilers in regards to tube failure. |
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How does the immersion heater boiler differs from the electrode boiler? |
No electric current travels through the water. |
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Control of the immersion heater boiler is accomplished by turning on and off the power supply to: |
the elements. |
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Immersion heaters are arranged in the boiler so that they are easily accessible for: |
maintenance or replacement. |
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Another downside to immersion type boilers: |
expensive to operate. |
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An immersion type electric boilers capacity can be as high as: |
1500 kW. |
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Control of the immersion heater boiler is done by turning on and off the: |
number of elements. |
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Radiographic images are taken using: |
X-rays. |
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Firetube boilers have their tubes fixed into flat steel plates called: |
Tube sheets. |
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Boiler shells and drums commonly range in thickness from _____ to _____. |
6 - 250 mm. |
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One non-destructive test on the boiler is the _____ test. |
X-ray. |
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The circumferential weld joints that attach dished heads to a boiler drum are: |
butt joints. |
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Single-welded butt joints:
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have filler metal applied from only one side of the plate. |
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Who checks that the welding procedures used by a manufacturer in the fabrication of a boiler are correct? |
An authorized inspector. |
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The circumferential seam of a riveted boiler shell utilised the: |
single or double riveted lap joint. |
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A tube expander is used to: |
Expand and flare the tube. |
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Beading the tube ends in a firetube boiler: |
prevents overheating of the tube ends. |
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Tubes for high pressure service are usually: |
seamless construction. |
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Boiler stays are: |
used to support flat surfaces in a boiler. |
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Stays are not normally required in watertube boilers because: |
The pressure parts have no flat surfaces. |
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In firetube boilers, _____ stays are often used to support the flat surfaces above the tubes: |
Diagonal. |
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A major force that holds the manway door of the boiler drums in place during operation is the: |
Boiler pressure. |
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Man holes are: |
Provided for inspection purposes. |
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Corrugated furnaces permit what? |
expansion and contraction with reduced stress. |
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A morrison furnace is found where? |
In firetube boilers. |
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Top supported boilers: |
expand vertically downwards. |
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One advantage of a water cooled boiler furnace is: |
less brickwork required. |
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One way to increase natural draft is to: |
Install a higher chimney. |
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A characteristic of mechanical draft is that the draft: |
Is properly regulated during all firing conditions. |
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Natural draft is produced in a boiler furnace when: |
Gases in the stack have less mass than an equal column of outside air. |
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In a forced draft course, the furnace pressure is: |
Above atmospheric pressure. |
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An induced draft fan operates at much higher temperatures than a _____. |
FD fan. |
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When an air heater is used in a boiler: |
It increases the efficiency of the boiler. |
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In a balanced draft course, the air heater is located: |
Between ID fan and boiler. |
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The advantage of a steel stack over a reinforced concrete stack is that a steel stack: |
Has lower initial cost. |
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With an axial flow fan, the air flow: |
Is parallel to the fan shaft. |
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When draft is produced by natural means: |
Cooler air surrounding the boiler increases draft. |
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A more durable chimney for a power plant application is the _____ chimney. |
Reinforced concrete. |
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Boiler chimneys are commonly lined with: |
Fire brick. |
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The most efficient operation of a fan occurs when: |
The fan speed is just enough to meet the air demand. |
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Proper draft is important to the plant operator because it: |
produces efficient combustion. |
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When the least amount of energy is desired to drive a fan with variable output control, the type of control used would most likely be: |
Variable speed coupling. |
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With fan output damper control: |
The fan air pressure increases with a decrease in air flow. |
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The inclined U tube manometer is more accurate than a _____. |
"U" tube manometer. |
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A diaphragm type pressure gauge is used to measure very _____ _____. |
small pressures. |
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If one end of a "U" tube is connected to the discharge of a forced draft fan the: |
The open end will have a higher liquid level than the connection end. |
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Post weld heat treatment removes residual stresses left by: |
welding. |
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The area below the tubes is often supported by ______ or _____ stays. |
Longitudinal or through. |
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Elliptical manhole opening size: |
305 - 406 mm. (B51) |
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Diameter of a circular manhole must be: |
380 mm. (B51) |
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ASME Elliptical manhole opening size: |
300 mm - 400 mm. |
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ASME diameter for a circular manhole: |
380 mm. |
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ASME handholes: |
70 mm - 89mm. |
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Three types of furnace walls: |
1. Welded fin 2. Tangent 3. Flat stud |
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A draft gauge on a furnace indicates the draft in: |
mm of water column. |