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86 Cards in this Set
- Front
- Back
what term is used to describe a burner flame tha moves back through the burner nozzle? |
flashback |
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through which device is fuel discharged to the burner |
the orfice |
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which type of burner prodcues a single large flame? |
a singe or mono port |
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list four common types of multiple port burners |
1. drilled port 2. drilled pipe 3. ribbon port 4. slotted port |
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maximum and minimum port diameters for drilled port burners |
max. no 29 min. no 42 |
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which type of power burner has combustion air supplied by a fan or blower under suffiecent pressure to overcome the restriction of the burner and the applicance ? |
force draft burner |
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which type of burner has a fan located downstream of the combustion zone? |
induced draft burner |
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what provides kinetic energy to the air required for a premixing inspirator type burner? |
the gas pressure issuing from an oridice into gas jet mixer |
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what type of burner provides complete premixing using mechanical mixers |
blower mix |
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what device is used to regulate gas supply to an asourator type burner |
zero govenor |
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how to do you correct: a lifting flame |
reduce primary air |
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how to do you correct: flashback |
reduce primary air
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how to do you correct: yellow tipping |
increase primary air |
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how to do you correct: flam roll out (steady) |
reduce over -firing, remove possible vent blockage |
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which atmospheric burner are most susceptible to flashback |
monoport
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what helps to keep the flame retained at the burner port of a monoburner? |
pilot |
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what is a multiport burner susceptible to? |
clogging from lint |
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what type of burner: has air drawn into burner by venturi action? |
atmospheric burn |
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what type of burner: has air supplied to burner under enough pressure to overcome resistance of burner only? |
fan assist |
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what type of burner: has air supplied to burner under enough pressure to overcome the resistance of the burner and the applicance ? |
power burn |
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what type of burner: has air and gas mixed completely before introduction to the chamber by inspiration, aspiration or blower mix method? |
premixed burner |
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what type of venting system: has air drawn in by a vaccum |
inspector |
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what type of venting system: has air moving through the burner creating a neg. pressure that draws the gas into the burner to be mixed? |
aspirator |
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what type of venting system: has gas drawn in by neg. pressure created by a blower that is also drawn in air for combustion? |
block |
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what type of venting system: has a regulator designed to supply gas at or below atmo. pressure when a vaccum is induced on it |
zero govenor |
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a burner must be capable of _______________ so fuel is completely burned |
mixing fuel gases and air together |
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a mulitport burner flame front should not _______ as it moves from port to port |
delay |
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a stable flame will not ______________________ |
waver, flashback, or lift off |
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there needs to be uniform heating across the burner surface; otherwise, uneven heat causes great stress on the ______________/ |
heat exchanger |
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burners turn down ratio is the accepted range of input for ________________ |
Satisfactory combustion |
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t.d.r. means that the burner can fire between ____% and _____% of the ________________ and still maintain a stable flame |
20% to 100% maximum rated input |
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if btu/h input goes below ______%of max gas flow rate, flame will queech |
20% |
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stable flame has characteristics by high appliance efficiency & primary and secondary air supples are correct |
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single port burners (mono) are simple in design and need about 50% primary air to avoid yellow tipping |
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multiport burners are most common and flames are better spread apart |
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power burners can be used when air supply and venting is assisted by draft fan and assisted by blower |
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when heat is applied to a rod and tub sensing device uts gas valve |
opens or closes |
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thermocupes are power combustion safety circuits that |
have constant pilots , greater voltage, have a safety shutoff value if pilot light goes out
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thermopiles are made of.. |
several thermcouples in series |
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if there is too much primary air, the gas flame can... |
lift off and
make noise |
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a furance with a vertical air flow through heat exchange er and the blower compartment beneath heather exchanger is an ... |
upflow |
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the proper typical color of a gas flame is.. |
sharp all blue |
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primary air adjusters on atmospheric type gas burners usually consist of |
1. butterflu shutters 2. sliding sleeves 3. set screws |
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in a conventional gas furnace , the hot flue gases are |
vented by natural convection |
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T/F: if flue gases ae not vented properly, CO poison could result |
true |
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T/F: liquidifed petroleym us geavier than and can cause suffocation if not handled properly |
true |
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T/F: a gas furance designed for use with natural gas can be used with LP with no system modifications |
false |
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T/F: a gas flame will carry eletrical energy |
true |
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the gas flame will lift off burner and be noisy if it recieves too much primary air |
true |
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natural gas utiities supply gas with a heat content of about 1000 btu/cu ft. |
true |
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three main products of complete combustion of naturla and LP gas are |
N2 CO2 water vapour heat |
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a furnance with a hortizontal heat exchanger and a propeller fan for moving aur through the h.e. is called a... |
unit heater |
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the dangerous by-product of poor combustion is.. |
CO and aldihydes |
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spark ignition is important for roof top or package units located outdoors because _____ problems. |
wind |
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on a gas furnace, what enggizes the blower motor in the heat mode |
eletric timer, fan limit switch |
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when a gas furnace ignites and is under "full fire" why does the fan not come on immediately |
heat exhaust needs more time to warm up |
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why is "inches of water column" used to measure gas pressure instead of psig |
accuracy |
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what is the difference between a yellow flame and a orange flame |
yellow - more seconary orange - dust or lint |
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the flame in a gas furnace is burner with heavy yellow tips |
needs more primary |
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while the furnace is operating, heated air and flue products spill out of the burner compartment, what is the problem |
blockage |
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when the burner ignites, the burner flame is normal until the blower starts at this time, continuous roll out occurs , what is the problem? |
cracked heat exchange |
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why do propane and butane has furnaces require 100% shut off in the event of a power outages? |
specific gravity |
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FURNACES: A RETURN AND SUPPLY DUCT ARE BOTH OF TOP IT IS A ... |
LOW BOY |
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FURNACES: A BLOWER LOCATED BELOW A HEAT EXCHANGE IS A... |
UPFLOW |
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FURNACES: IS PRIMARILY USED IN CRAWL SPACE |
HORTZONTAL |
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FURNACES: BLOWER LOCATED ABOVE HEAT EXCHANGE |
DOWNFLOW |
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NAME THREE MAJOR WAYS IN WHICH HEAT IS TRANSFERRED |
1. CONDUCTION 2. CONVECTION 3. RADIATION |
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IN WHICH DIRECTION DOES HEAT ENGERY FLOW? |
WARM TO COLD |
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WHAT HAPPENS WHEN A FLUID IS HEATED? |
IT EXPANDS AND BECOMES LIGHTER |
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WHAT CONTROLS THE DRYING PERIOD OF A GAS FIRED CLOTHE DRYER |
MOISTER SENSOR OR TIMER |
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WHAT NORMALLY CONTROLS THE AUTOMATIC GAS VALUE FOUND ON A CORCED WARM-AIR FURANCE |
THERMOSTAT |
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WHERE IS THE BLOWER LOCATED ON A DOWN-FLOW FURNACE |
ABOVE HEAT EXCHANGER |
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what is heat transferred from a cook top burner |
conduction |
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name two ways in which the burner can be controlled on a unit heater |
wall mounted switch |
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what are three conditions are regulated in hot water boiler |
firing at boiler boiler water temp circuting |
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which type of water heater system can be used for both domestic hot water supply and space heating |
conbination unit |
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three types a gasfired units in a single room |
space heater wall furnace base board heater |
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senses the operation of a cicuating pump |
flow switch |
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a water temperature sensing device that will shut off the burner if the temperature exceeeds desred range |
high temperature aqua stat |
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SHUTS OFF THE BURNER IN THE EVENT THAT THE PRESSURE IN A BOILER EXCEEDS DESIRED RANGE |
HIGH LIMIT |
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TURNS A STEAM BOILER ON AND OFF TO MAINTAIN A DESIRED TEMP |
OPPERATING PRES. SWITCH |
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TURNS A BOILER OR WATER HEATER ON TO KEEP DESIRED WATER TEMP |
LOW WATER CUT OFF |
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ALLOWS HOT WATER TO ESCAPE FROM A SYSTEM IF THE PRESSURE EXCEEDS A PRESET MAX. VALUE |
PRESSURE RELIEF VALVE |
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SHUTS DOWN BURNER IN THE EVENT OF A FAILURE TO VENT FLUE PRODUCT |
FLAME ROLL OUT SWITCH |
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ALLOWS WATER TO EXCAPE IF TEMP. OR PRESS. EXCEEDS A PRESET VALUE INSIDE AHOT WATER HEATER |
TEMP. AND PRESSURE RELIEF VALVE. |
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