DC Boiler Exam Prep Questions and Answers Graded A+
Area of a rectangle - -Length x Width Celsius to Fahrenheit - -°F = (1.8 x °C) - 32
Area of a Circle - -.7854 x Diameter² Fahrenheit to Rankine - -°R = °F + 460
Volume of a Box - -Length x Width x Celsius to Kelvin - -K = °C +273.15
Height
Charles' First Law - -Volume1 / Pressure1
Volume of a Cylinder - -.7854 x Diameter² = Volume2 / Pressure2
x Length
Charles' Second Law - -Pressure1 /
Circumference of a Circle - -π x Diameter Temperature1 = Pressure2 / Temperature2
Unit of Force - -Pound (lb) Boyle's Law - -Pressure1 x Volume1 =
Pressure2 x Volume2
Formula for Force - -Pressure ÷ Area
General Gas Law - -(Pres1 x Vol1)/ Temp1
= (Pres2 x Vol2)/Temp2
Unit of Work - -in-lb or ft-lb
Formula for Levers - -Resistance x
Formula for Work - -Force x Distance DistanceR = Effort x DistanceE
Unit of Power - -ft-lb/min Formula for Inclined Planes - -Force x
Length = Resistance x Height
Formula for Power - -= Work ÷ Time
or (Force x Distance) ÷ Time Formula for Wheel & Axel - -Force x
DistanceF = Resistance x DistanceR
Formula for Mechanical Horsepower - -=
Power ÷ 33,000 ft-lb/min Torque - -Force x Radius
Fahrenheit to Celsius - -°C = (°F - 32) ÷ Safe Working Pressure of a Riveted Boiler (SWP)
1.8 - -(Area of Staybolt x Stress Constant of
Staybolt) ÷ Area Covered by Staybolt or = (a x C)
÷A
, DC Boiler Exam Prep Questions and Answers Graded A+
per hour - -34.5 lbs/hr
Area Covered by Staybolt - -= Pitch x Pitch
1 Boiler Horsepower = x Btu/hr - -33,475
Longitudinal Stress - -(P x D x L) / 2t Btu/hr
P = Pressure
D = Diameter
L = Length 1 BHP = x ft² of heating surface (general) -
t = thickness of steel -10 ft² heating surface
Boiler Heating Surface (tubes) = - -= C x L Volume of water increases by x percent when it
x# flashes to steam - -x 1600
C = Circumference of tubes
L = Length of tubes
# = Number of tubes Thermal Efficiency (TE) = - -= Lbs Steam
HS = π x Diameter x Length x Number of Tubes per hour [Hs -(fwt° -32)] ÷ Units of Fuel per hour x
Btu content per unit of fuel
Hs = Btu content of steam
Watts per Boiler Horsepower - -746 Watts fwt = feed water temperature
Horsepower formula - -= ft-lb/min ÷ 33000 Developed Boiler Horsepower (DBHP) = - -
ft-lb/min = (Pounds of Steam per hour (Ws) x FE) ÷ 34.5
Ws = Lbs of steam per hour
FE = Factor of Evaporation
ft-lb formula for a pump - -= gpm x 8.33 x
head (ft)
Maximum Allowable Working Pressure (MAWP) -
-= (TS x t x E) / FS x r
Factor of Evaporation (FE) = - -= [Hs - (tfw- TS = Tensile Strength of steel
32)] ÷ 970.3 t = thickness of steel
Hs = Enthalpy of steam E = Efficiency of joint
tfw = temperature of feed water FS = Factor of Safety
r = radius of boiler drum
Latent Heat of Vaporization for Water - -
970.3 Btu/lb Bursting Pressure (BP) - -= (TS x t x E) / r
TS = Tensile Strength of steel
t = thickness of boiler plate
Latent Heat of Fusion for Water - -144 E = efficiency of joint
Btu/lb r = radius of boiler shell
1 Boiler Horsepower = x lbs of steam generator Expansion (E) of Piping = - -= L x Cle x (T1
Area of a rectangle - -Length x Width Celsius to Fahrenheit - -°F = (1.8 x °C) - 32
Area of a Circle - -.7854 x Diameter² Fahrenheit to Rankine - -°R = °F + 460
Volume of a Box - -Length x Width x Celsius to Kelvin - -K = °C +273.15
Height
Charles' First Law - -Volume1 / Pressure1
Volume of a Cylinder - -.7854 x Diameter² = Volume2 / Pressure2
x Length
Charles' Second Law - -Pressure1 /
Circumference of a Circle - -π x Diameter Temperature1 = Pressure2 / Temperature2
Unit of Force - -Pound (lb) Boyle's Law - -Pressure1 x Volume1 =
Pressure2 x Volume2
Formula for Force - -Pressure ÷ Area
General Gas Law - -(Pres1 x Vol1)/ Temp1
= (Pres2 x Vol2)/Temp2
Unit of Work - -in-lb or ft-lb
Formula for Levers - -Resistance x
Formula for Work - -Force x Distance DistanceR = Effort x DistanceE
Unit of Power - -ft-lb/min Formula for Inclined Planes - -Force x
Length = Resistance x Height
Formula for Power - -= Work ÷ Time
or (Force x Distance) ÷ Time Formula for Wheel & Axel - -Force x
DistanceF = Resistance x DistanceR
Formula for Mechanical Horsepower - -=
Power ÷ 33,000 ft-lb/min Torque - -Force x Radius
Fahrenheit to Celsius - -°C = (°F - 32) ÷ Safe Working Pressure of a Riveted Boiler (SWP)
1.8 - -(Area of Staybolt x Stress Constant of
Staybolt) ÷ Area Covered by Staybolt or = (a x C)
÷A
, DC Boiler Exam Prep Questions and Answers Graded A+
per hour - -34.5 lbs/hr
Area Covered by Staybolt - -= Pitch x Pitch
1 Boiler Horsepower = x Btu/hr - -33,475
Longitudinal Stress - -(P x D x L) / 2t Btu/hr
P = Pressure
D = Diameter
L = Length 1 BHP = x ft² of heating surface (general) -
t = thickness of steel -10 ft² heating surface
Boiler Heating Surface (tubes) = - -= C x L Volume of water increases by x percent when it
x# flashes to steam - -x 1600
C = Circumference of tubes
L = Length of tubes
# = Number of tubes Thermal Efficiency (TE) = - -= Lbs Steam
HS = π x Diameter x Length x Number of Tubes per hour [Hs -(fwt° -32)] ÷ Units of Fuel per hour x
Btu content per unit of fuel
Hs = Btu content of steam
Watts per Boiler Horsepower - -746 Watts fwt = feed water temperature
Horsepower formula - -= ft-lb/min ÷ 33000 Developed Boiler Horsepower (DBHP) = - -
ft-lb/min = (Pounds of Steam per hour (Ws) x FE) ÷ 34.5
Ws = Lbs of steam per hour
FE = Factor of Evaporation
ft-lb formula for a pump - -= gpm x 8.33 x
head (ft)
Maximum Allowable Working Pressure (MAWP) -
-= (TS x t x E) / FS x r
Factor of Evaporation (FE) = - -= [Hs - (tfw- TS = Tensile Strength of steel
32)] ÷ 970.3 t = thickness of steel
Hs = Enthalpy of steam E = Efficiency of joint
tfw = temperature of feed water FS = Factor of Safety
r = radius of boiler drum
Latent Heat of Vaporization for Water - -
970.3 Btu/lb Bursting Pressure (BP) - -= (TS x t x E) / r
TS = Tensile Strength of steel
t = thickness of boiler plate
Latent Heat of Fusion for Water - -144 E = efficiency of joint
Btu/lb r = radius of boiler shell
1 Boiler Horsepower = x lbs of steam generator Expansion (E) of Piping = - -= L x Cle x (T1
