DC 1ST CLASS BOILER QUESTIONS AND CORRECT ANSWERS

DC 1ST CLASS BOILER QUESTIONS AND
CORRECT ANSWERS

MovingA2bladingA2inA2whichA2spaceA2betweenA2bladesA2isA2theA2sameA2sizeA2atA2theA2blad
ingA2inlet,A2andA2theA2bladingA2outlet.A2-A2Ans--ImpulseA2Blading

ToA2blowdownA2aA2boilerA2equippedA2withA2aA2quickA2openingA2andA2slowA2openingA2valv
eA2onA2theA2bottomA2blowdownA2line,A2the_________.A2-A2Ans--
quickA2openingA2valveA2isA2openedA2firstA2andA2closedA2last.

HardnessA2ofA2waterA2isA2theA2measurementA2inA2ppmA2ofA2________A2andA2________A2i
nA2theA2water.A2-A2Ans--calciumA2andA2magnesium

AA2pumpA2deliversA2175A2gallonsA2perA2minuteA2againstA2aA2pressureA2ofA255A2psi;A2theA2s
uctionA2pressureA2isA215A2psi.A2IfA2aA2pumpA2isA280%A2efficient,A2whatA2isA2theA2horsepow
erA2needed?A2-A2Ans--HP=5.1A2HP=A2(HeadA2inA2Feet)A2xA2(WeightA2inA2Lbs.)/
A233,000A2xA2Efficiency


aA2duplexA2double-actingA2reciprocatingA2feedA2waterA2pumpA2has____A2-A2Ans--
twoA2steamA2PistonsA22A2toA22A22/2A2timesA2largerA2inA2areaA2thanA2theA2waterA2piston

NameA2aA2techniqueA2toA2controlA2theA2nitrousA2oxideA2emissions.A2-A2Ans--
SelectiveA2CatalyticA2Reduction

SpallingA2inA2aA2boilerA2occursA2inA2theA2____?A2-A2Ans--CombustionA2chamber

AA2technologyA2inA2whichA2solidA2wasteA2isA2heatedA2inA2anA2oxygenA2starvedA2atmospher
eA2toA2breakA2downA2theA2solidsA2intoA2aA2gasA2isA2calledA2______?A2-A2Ans--Pyrolysis

WhatA2isA2theA2primaryA2purposeA2ofA2usingA2wetA2scrubbers?A2-A2Ans--
ToA2removeA2sulfurA2dioxides

TheA2thermalA2efficiencyA2ofA2aA2boilerA2withA2aA2stackA2temperatureA2ofA2750°FA2andA2an
dA2aA2furnaceA2temperatureA2ofA23200°FA2is_______?A2-A2Ans--75%A2((3200-750)/
3200)A2xA2100

________isA2aA2water-
purificationA2processA2inA2whichA2theA2waterA2toA2beA2treatedA2isA2pressurizedA2andA2appli
edA2againstA2theA2surfaceA2ofA2aA2semipermeableA2membrane.A2-A2Ans--
ReverseA2osmosis

TheA2airflowA2switchA2atA2theA2burnerA2fanA2housing______.A2-A2Ans--
EnsuresA2theA2primaryA2airA2fanA2isA2functioning

, HowA2manyA2inchesA2ofA2steamA2spaceA2inA2aA2cylinderA2ofA2anA2engineA212"x28"A2andA2t
heA2strokeA2isA25/8A2ofA2itsA2fullA2travel?A2-A2Ans--
1978.A2V=AxLA2V=3.14(6x6)x28x.625=A21978

WhatA2isA2theA2horsepowerA2requirementA2ofA2aA2pumpA2thatA2movesA22500A2gpmA2ofA2w
aterA2againstA2aA2headA2ofA2475'A2ifA2theA2pumpA2isA2operatingA2atA258%A2efficiency?A2-
A2Ans--516.8A2HP=HeadA2xA2Weight/
33000A2xA2efficiency.A2(HeadA2=475,A2WeightA2=A22500gpmA2xA28.33)A2(475xA220825)/
19140

AA2______A2isA2theA2conditionA2thatA2isA2beingA2controlledA2-A2Ans--processA2variable

AlthoughA2boilerA2tubesA2andA2boilerA2drumsA2withstandA2theA2sameA2pressure,A2theA2wall
sA2ofA2theA2boilerA2tubesA2areA2muchA2thinnerA2becauseA2______.A2-A2Ans--
TheA2tubesA2areA2muchA2smallerA2inA2diameter

AA2leadA2sulfideA2cellA2detects_____.A2-A2Ans--BurnerA2pilotA2andA2mainA2flame

WhichA2ofA2theA2followingA2indicatesA2aA2malfunctionA2inA2theA2DCA2heater?
A21.A2TheA2boilerA2requiresA2excessiveA2amountsA2ofA2oxygenA2absorbingA2chemicals.
2.WaterA2andA2steamA2areA2enteringA2theA2DCA2heaterA2atA2theA2sameA2temperature.A2-
A2Ans--BothA21A2&A22


______A2isA2theA2plasticityA2exhibitedA2byA2aA2materialA2underA2tensionA2loading.A2-
A2Ans--Ductility


InA2aA2pressureA2atomizingA2fuelA2oil-
burner,A2atomizationA2ofA2fuelA2isA2producedA2byA2theA2_______.A2-A2Ans--
BurnerA2tipA2andA2highA2pressureA2fuel

TheA2endsA2ofA2boilerA2tubesA2areA2securedA2toA2headersA2by______.A2-A2Ans--
Expanding

A_______A2isA2aA2processA2conditionA2thatA2mustA2beA2metA2beforeA2aA2certainA2actionA2
mayA2beA2taken.A2-A2Ans--Permissive

______A2isA2theA2abilityA2ofA2aA2materialA2toA2returnA2toA2itsA2originalA2shapeA2afterA2beingA
2deformed.A2-A2Ans--Resiliency


InA2aA2three-elementA2feedwaterA2regulatingA2system,A2__________A2areA2measured.A2-
A2Ans--steamA2flow,A2feedwaterA2flow,A2andA2waterA2level


AA2________A2isA2aA2highlyA2efficientA2ion-
exchangeA2processA2inA2whichA2resinA2isA2regeneratedA2withA2sulfuricA2acidA2inA2theA2firstA
2vesselA2andA2causticA2sodaA2inA2theA2secondA2vesselA2-A2Ans--demineralizer