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26 Cards in this Set
- Front
- Back
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The cut-off switch opens and cuts off power to the fuel valve when the boiler level in the glass shows at least _____ of water A) 10mm B) 20mm C) 5mm D) 40mm |
B) 20mm |
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A small steam heating boiler with a combination low-water cutoff and feed water control must, by code, have a second, dedicated: A) feedwater pump B) gauge glass C) low-water cutoff D) feedwater control valve E) condensate return line |
C) low-water cutoff |
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In some unattended heating boilers the low-water cutoff also helps maintain water level by opening a/an _______ before low water level is reached. A) electric feeder valve B) second feed pump C) blowdown valve D) auxiliary feedline E) feedwater bypass |
A) electric feeder valve |
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When a boiler equipped with a combination feedwater controland low-water cutoff device shuts down due to a low-watercondition a) the feedwater flow will also stop b) level must be restored to above the cutoff line beforethe unit can be restarted c) it can be restarted by simply resetting the cutoff switch d) a manual reset switch must be used e) a prepurge will not be necessary |
b) level must be restored to above the cutoff line before it can be restarted |
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An electric feeder valve will a) eliminate the need for a low-water fuel cutoffb) prevent a low-water trip c) open before the low-water cutoff line is reached d) require manual action to open e) open after the unit trips on low-water |
c) open before the low-water cutoff line is reached |
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A float operated mechanical feeder valve shoulda) be a normally closed valve b) open just after the low-water cutoff switch opens c) be located above the water column d) not be deemed a stand-by device e) not open until the level is well below the feed pumpcut-in level |
e) not open until the level is well below the feed pump cut-in level |
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In nearly all LP steam heating systems the feed water a) is usually condensate b) requires daily close scrutiny of chemical values c) is a high make-up percentage d) must be deaerated e) requires preheating in an economizer |
a) is usually condensate |
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A Hartford loop will a) eliminate the need for venting a steam heating system b) ensure continuous circulation of a hot water system c) prevent steam from entering a steam pressure gage d) prevent boiler water level from going below the LPWL e) prevent the draining of an expansion tank |
d) prevent boiler water from entering a steam pressure gauge |
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Because of variations in flow rate, nearly all large steamheating plants utilize a) an economiser b) a deaerator c) a condensate receiver d) multiple boilers e) steam pressure regulating valves |
c) a condensate receiver |
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Heating plants with multiple boilers often havea) independent boiler feedwater control from a header b) individual feedwater systems c) feedwater pressure regulating valves for each boiler d) separate condensate receivers e) a common feedwater control valve |
a) independent boiler feed water control from a header |
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Dissolved oxygen in condensate a) will cause pitting in a boiler b) can cause pitting on the return lines c) causes grooving of the condensate lines d) cannot be removed with chemicals e) necessitates the installation of a deaerator |
a) will cause pitting in a boiler |
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Neutralizing amines a) raise the pH of condensate b) lower the pH of boiler water c) eliminate boiler pitting d) can cause return grooving e) absorb carbon dioxide |
a) raise the pH of condensate |
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The result of a condensate receiver which is too small couldbe a) high boiler water level(s) b) loss of condensate to the sewer c) loss of make-up water d) unacceptable high steam pressures e) low make-up water flow rates |
b) loss of condensate to the sewer |
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A feedwater make-up system should a) utilize demineralizers b) utilize a deaerator c) be able to satisfy normal firing needs d) always be softened water e) be able to satisfy the needs of at least one boiler in amultiboiler plant |
c) be able to satisfy normal firing needs |
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Equalizing lines on a condensate receiver float chamber a) will dampen level fluctuations b) keep receiver level equal to boiler level c) maintain make-up flow equal to condensate flow d) eliminate the need for a make-up level control valve e) maintains equal flow of condensate to multiple boilers |
a) will dampen level fluctuations |
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A condensate receiver low level cutoff switch willa) act to open a make-up solenoid b) stop the feedpump thereby preventing damage to it c) act to close boiler fuel valve(s) d) sound an alarm e) cause the make-up valve to close |
b) stop the feed pump thereby preventing damage to it |
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A condensate receiver low level cut-off switch will: a) act to open a make-up solenoid b) stop the feed pump thereby preventing damage to it c) act to close boiler fuel valves d) sound an alarm e) cause the make-up valve to close |
b) stop the feed pump thereby preventing damage to it |
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Dissolved oxygen in condensate: a) will cause pitting in a boiler b) can cause pitting on the return lines c) causes grooving of the condensate lines d) cannot be removed with chemicals e) necessitates the installation of a dearator |
a) will cause pitting in a boiler |
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The cut-out level of the feed water control switch is: a) the level at which the cut-off switch opens b) the level at which the supply switch closes c) the level at which the supply switch starts the feed water pump d) the highest operating level of the water in the boiler e) the lowest operating level of the water in the boiler |
d) the highest operating level of the water in the boiler |
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Which of the following is true about a well balanced steam heating system? a) the amount of condensate returning from the heating system is greater than the amount of steam leaving the boiler b) the amount of condensate returning from the heating system is less than the amount of steam leaving the boiler c) the amount of condensate returning from the heating system is equal to the amount of steam leaving the boiler d) the condensate return is normally not steady e) the low-water cutoff is not required |
c)the amount of condensate returning from the heating system is equal to the amount of steam leaving the boiler |
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A float operated mechanical feeder valve should: a) be a normally closed valve b) open just after the low-water cutoff switch opens c) be located above the water column d) not be deemed a standby device e)not open until the level is well below the feed pump cut-in level |
e)not open until the level is well below the feed pump cut-in level |
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The result of bleeding some of the water out of the control line on the condensate receiver will be: a) causing the water level in the receiver to drop b) causing the makeup valve to close in c) increasing the force on the diaphragm of the makeup valve d) causing the pressure in the control line to drop e) causing the pressure in the control line to increase |
d) causing the pressure in the control line to drop |
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The two common gaseous impurities found in condensate are: a) O2 and N2 b) N2 and air c) O2 and CO2 d) CO2 and CO e) O2 and H2 |
c) O2 and CO2 |
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The boiler must be equipped with a second low-water cutoff when: a) the first device is also used to control the feed water flow b) the auxiliary water supply is not able to maintain a safe water level in the boiler c) the normal source of supply is either insufficient or fails altogether d) the second source of supply is controlled by an electric feeder valve e) the second source of supply is controlled by a mechanical feeder valve |
a) the first device is also used to control the feed water flow |
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The feed water supply to most steam heating boilers is usually controlled by a: a) diverter b) return trap c) float switch d) Hartford loop e)gage glass |
c) float switch |
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Many heating boilers are equipped with a second source of water supply (usually city water) that starts feeding water into the boiler when: a) the water level reaches the cut-in level of the feed water pump b) the burner flame goes out c) the normal source of supply is either insufficient or fails altogether d) low-water cutoff switch opens e) boiler shuts down |
c) the normal source of supply is either insufficient or fails altogether |
