FDNY A-35 Questions and Answers 2025
AirAcompressorsApower...A-ACORRECTAANSWERSA-
(1)AindustrialAequipmentAandA(2)AconstructionAtools
ExamplesAofAequipmentApoweredAbyAairAcompressorA-ACORRECTAANSWERSA-
pneumaticAwrenches,AliftsAinAautoAserviceAstations,ApaintAsprayAbooths
AirAcompressorsAenable...A-ACORRECTAANSWERSA-
(1)AefficientArepairAofAallAtypesAofAvehicles;AandA(2)AfacilitateAtheirAsafeAoperationAonApublicA
thoroughfares
PermitAisArequiredAforAairAcompressorA-ACORRECTAANSWERSA-
thatAcompressesAairAaboveA100APSI
TypesAofAairAcompressorsA-ACORRECTAANSWERSA-(1)Areciprocating;
(2)Acentrifugal;
(3)Asolar;Aand
(4)Arotary
*DifferenceAisAtheAwayAinAwhichAtheyAcompressAair
HowAdoAairAcompressorsAworkA-ACORRECTAANSWERSA-
takeAtheAairAinAaAroomAandAforceAitAintoAaAcontainerAUNDERAPRESSURE.ATheAmoreAairAfo
rcedAintoAtheAcontainer,AtheAgreaterAtheApressure.ACompressedAairAcanAbeAdischargedAfro
mAtheAcontainerAatAaAcontrolledArate.
MostAcommonAairAcompressorA-ACORRECTAANSWERSA-Reciprocating
AirAcompressorsAareAsometimesAcalledA-ACORRECTAANSWERSA-airApumps
AirAcompressorsAcanAbeApoweredAby:A-ACORRECTAANSWERSA-(1)AelectricAmotors;
(2)AinternalAcombustionAengines;Aor
(3)AsteamAturbines
ExplosionsA&AairAcompressorsA-ACORRECTAANSWERSA-
IfAthereAisAaAbuildAupAofAflammableAgasesA(ex:AinAserviceAstationsAandAworkshops),AthoseA
gasesAareAheavierAthanAairAandAfallAtoAtheAfloorAbeforeAspreadingAoutward.ATheseAgasesAa
reAeasilyAignitedAbyAsparksAandAhighAtemperatures--
whichAINCLUDESAtheAheatAgeneratedAbyAanAairAcompressor.
ToAavoidAexplosionsAw/AairAcompressorsA-ACORRECTAANSWERSA-
RaiseAairAcompressorAatALEASTA5AfeetAaboveAgroundAlevelAsoAthatAnoAflammableAgasesAa
reAdrawnAintoAtheAcompressor.AToAmeetAtheAheightArequirementAyouAcanAplaceAcompress
orAonAaAshelfAorAbenchAORAtheAairAreceiverAtankAmayAbeAturnedAandAstoodAonAendAw/AtheAa
irAcompressorAboltedAtoAtheAtopAofAtheAtank.
PowerAtoAairAcompressorA-ACORRECTAANSWERSA-
entireAunitAisAdrivenAbyAanAelectricAmotor.AMotorAactivatesAaAseriesAofAdriveAbelts.ABeltsApo
werAtheAmovingApartsAofAtheAunit--likeAw/ApowerAsteeringAandAalternatorAinAautomobile
CompressionAChamberAoperationA-ACORRECTAANSWERSA-
AirAisAcompressedAinAcompressionAchamberAwhichAconsistsAofAaAPISTONAinsideAaACYLIN
DER.APistonAmovesAupAandAdown.A
, WhenApistonAmovesAdownA--
>drawsAairAintoAcylinder,AthroughAINTAKEAVALVEA(valveAautomaticallyAopensAwhenApisto
nAmovesAdown).
WhenApistonAmovesAup--
>airAisAcompressedA(intakeAvaleAautomaticallyAclosesAtoAavoidAairAescapingAfromAcylinder)
.
AirARecieverAOperationA-ACORRECTAANSWERSA-
WhenAairApressureAreachesAaAcertainAlevel,AitAforcesAopenAaADISCHARGEAVALVEA(which
AisAspringAloaded).AThisAreleasesAcompressedAairAintoAairArecieverA(akaAairAtank),AwhichAisA
whatAsuppliesAcompressedAairAwhenAneeded.
SingleAStageAAirACompressorA-ACORRECTAANSWERSA-withAoneAcylinderAandAoneApiston
MultiAStageAAirACompressorA-ACORRECTAANSWERSA-
withAmoreAthanAoneApistonAandAcylinder.
EachAcylinderAwillAincreaseAtheApressureAofAtheAairAbyAtakingAairAfromAtheAdischargeAsideAo
fAtheApreviousAcylinderAandAincreasingAtheApressureAtoAaAnewAlevel.AOnceAitAreachesAtheAl
astAlevel,AtheApressurizedAairAisAdischargedAintoAtheAreciever.
AsAairAisAcompressedAitAbecomesA-ACORRECTAANSWERSA-heated.A
ThisAisAwhyAinAaAmultiAstageAairAcompressorAthereAisAanAintercoolerAbetweenAstagesAofAco
mpressor.
ExceptionAtoAsingleAstage/multiAstageAdistinctionA-ACORRECTAANSWERSA-
CAVEAT:AthereAareAairAcompressorsAwithAmultipleApistonsAandAcylindersAthatAareAsingleAst
ageAbutAtheseAareAonlyAtheAonesAwhereAeachAcylinderAdischargesAdirectlyAintoAairAreceiver
A(unlikeAaAtrueAmultiAstageAairAcompressor).
StorageAcontainersA-ACORRECTAANSWERSA-
someAsystemsAforceAtheAcompressedAairAfromAtheAreceiverAintoAstorageAcontainersAallowi
ngAitAtoAbeAusedAlaterAasAneeded.
SystemAofAConnectedAAirACompressorsA-ACORRECTAANSWERSA-
AirAforcedAfromAoneAcompressorAintoAanotherAseveralAtimeAtoAincreaseApressureAeachAtim
eAandAultimatelyAforcedAintoAaAhoseAlineAorAstorageAcontainer.A
UsedAwhenAthereAisAaAneedAforAairAunderAveryAhighApressure.
UnloadingAValveA-ACORRECTAANSWERSA-safetyAcomponent.
allowsAairAtoAescapeAcompressionAchamberAwhenAthereAisAaAstrainAonAtheAelectricalAmotor
.AThisAusuallyAoccursAinAtheAfirstAfewAcyclesAwhenAtheAcompressorAisAfirstAstarted.
AutomaticAinAmostAsystemsAbutAitAmayAbeAmanualAinAolderAcompressors.AFollowAinstructio
nAmanualAforAoldAcompressor.
PressureAGaugeA-ACORRECTAANSWERSA-safetyAcomponent.
IndicatesApressureAinsideAreceiver.ACFAholderAshouldApayAcloseAattentionAtoAreading.AMus
tANEVERAexceedAmanufacturer'sArecommendations.AIfAgreaterAthanArecommendedAlevelAt
AirAcompressorsApower...A-ACORRECTAANSWERSA-
(1)AindustrialAequipmentAandA(2)AconstructionAtools
ExamplesAofAequipmentApoweredAbyAairAcompressorA-ACORRECTAANSWERSA-
pneumaticAwrenches,AliftsAinAautoAserviceAstations,ApaintAsprayAbooths
AirAcompressorsAenable...A-ACORRECTAANSWERSA-
(1)AefficientArepairAofAallAtypesAofAvehicles;AandA(2)AfacilitateAtheirAsafeAoperationAonApublicA
thoroughfares
PermitAisArequiredAforAairAcompressorA-ACORRECTAANSWERSA-
thatAcompressesAairAaboveA100APSI
TypesAofAairAcompressorsA-ACORRECTAANSWERSA-(1)Areciprocating;
(2)Acentrifugal;
(3)Asolar;Aand
(4)Arotary
*DifferenceAisAtheAwayAinAwhichAtheyAcompressAair
HowAdoAairAcompressorsAworkA-ACORRECTAANSWERSA-
takeAtheAairAinAaAroomAandAforceAitAintoAaAcontainerAUNDERAPRESSURE.ATheAmoreAairAfo
rcedAintoAtheAcontainer,AtheAgreaterAtheApressure.ACompressedAairAcanAbeAdischargedAfro
mAtheAcontainerAatAaAcontrolledArate.
MostAcommonAairAcompressorA-ACORRECTAANSWERSA-Reciprocating
AirAcompressorsAareAsometimesAcalledA-ACORRECTAANSWERSA-airApumps
AirAcompressorsAcanAbeApoweredAby:A-ACORRECTAANSWERSA-(1)AelectricAmotors;
(2)AinternalAcombustionAengines;Aor
(3)AsteamAturbines
ExplosionsA&AairAcompressorsA-ACORRECTAANSWERSA-
IfAthereAisAaAbuildAupAofAflammableAgasesA(ex:AinAserviceAstationsAandAworkshops),AthoseA
gasesAareAheavierAthanAairAandAfallAtoAtheAfloorAbeforeAspreadingAoutward.ATheseAgasesAa
reAeasilyAignitedAbyAsparksAandAhighAtemperatures--
whichAINCLUDESAtheAheatAgeneratedAbyAanAairAcompressor.
ToAavoidAexplosionsAw/AairAcompressorsA-ACORRECTAANSWERSA-
RaiseAairAcompressorAatALEASTA5AfeetAaboveAgroundAlevelAsoAthatAnoAflammableAgasesAa
reAdrawnAintoAtheAcompressor.AToAmeetAtheAheightArequirementAyouAcanAplaceAcompress
orAonAaAshelfAorAbenchAORAtheAairAreceiverAtankAmayAbeAturnedAandAstoodAonAendAw/AtheAa
irAcompressorAboltedAtoAtheAtopAofAtheAtank.
PowerAtoAairAcompressorA-ACORRECTAANSWERSA-
entireAunitAisAdrivenAbyAanAelectricAmotor.AMotorAactivatesAaAseriesAofAdriveAbelts.ABeltsApo
werAtheAmovingApartsAofAtheAunit--likeAw/ApowerAsteeringAandAalternatorAinAautomobile
CompressionAChamberAoperationA-ACORRECTAANSWERSA-
AirAisAcompressedAinAcompressionAchamberAwhichAconsistsAofAaAPISTONAinsideAaACYLIN
DER.APistonAmovesAupAandAdown.A
, WhenApistonAmovesAdownA--
>drawsAairAintoAcylinder,AthroughAINTAKEAVALVEA(valveAautomaticallyAopensAwhenApisto
nAmovesAdown).
WhenApistonAmovesAup--
>airAisAcompressedA(intakeAvaleAautomaticallyAclosesAtoAavoidAairAescapingAfromAcylinder)
.
AirARecieverAOperationA-ACORRECTAANSWERSA-
WhenAairApressureAreachesAaAcertainAlevel,AitAforcesAopenAaADISCHARGEAVALVEA(which
AisAspringAloaded).AThisAreleasesAcompressedAairAintoAairArecieverA(akaAairAtank),AwhichAisA
whatAsuppliesAcompressedAairAwhenAneeded.
SingleAStageAAirACompressorA-ACORRECTAANSWERSA-withAoneAcylinderAandAoneApiston
MultiAStageAAirACompressorA-ACORRECTAANSWERSA-
withAmoreAthanAoneApistonAandAcylinder.
EachAcylinderAwillAincreaseAtheApressureAofAtheAairAbyAtakingAairAfromAtheAdischargeAsideAo
fAtheApreviousAcylinderAandAincreasingAtheApressureAtoAaAnewAlevel.AOnceAitAreachesAtheAl
astAlevel,AtheApressurizedAairAisAdischargedAintoAtheAreciever.
AsAairAisAcompressedAitAbecomesA-ACORRECTAANSWERSA-heated.A
ThisAisAwhyAinAaAmultiAstageAairAcompressorAthereAisAanAintercoolerAbetweenAstagesAofAco
mpressor.
ExceptionAtoAsingleAstage/multiAstageAdistinctionA-ACORRECTAANSWERSA-
CAVEAT:AthereAareAairAcompressorsAwithAmultipleApistonsAandAcylindersAthatAareAsingleAst
ageAbutAtheseAareAonlyAtheAonesAwhereAeachAcylinderAdischargesAdirectlyAintoAairAreceiver
A(unlikeAaAtrueAmultiAstageAairAcompressor).
StorageAcontainersA-ACORRECTAANSWERSA-
someAsystemsAforceAtheAcompressedAairAfromAtheAreceiverAintoAstorageAcontainersAallowi
ngAitAtoAbeAusedAlaterAasAneeded.
SystemAofAConnectedAAirACompressorsA-ACORRECTAANSWERSA-
AirAforcedAfromAoneAcompressorAintoAanotherAseveralAtimeAtoAincreaseApressureAeachAtim
eAandAultimatelyAforcedAintoAaAhoseAlineAorAstorageAcontainer.A
UsedAwhenAthereAisAaAneedAforAairAunderAveryAhighApressure.
UnloadingAValveA-ACORRECTAANSWERSA-safetyAcomponent.
allowsAairAtoAescapeAcompressionAchamberAwhenAthereAisAaAstrainAonAtheAelectricalAmotor
.AThisAusuallyAoccursAinAtheAfirstAfewAcyclesAwhenAtheAcompressorAisAfirstAstarted.
AutomaticAinAmostAsystemsAbutAitAmayAbeAmanualAinAolderAcompressors.AFollowAinstructio
nAmanualAforAoldAcompressor.
PressureAGaugeA-ACORRECTAANSWERSA-safetyAcomponent.
IndicatesApressureAinsideAreceiver.ACFAholderAshouldApayAcloseAattentionAtoAreading.AMus
tANEVERAexceedAmanufacturer'sArecommendations.AIfAgreaterAthanArecommendedAlevelAt