DC Boiler Exam Prep 2023(Formulas and constants used for the DC 3rd class boiler
exam)Verified 100%
Area of a rectangle - (answer)Length x Width
Area of a Circle - (answer).7854 x Diameter²
Volume of a Box - (answer)Length x Width x Height
Volume of a Cylinder - (answer).7854 x Diameter² x Length
Circumference of a Circle - (answer)π x Diameter
Unit of Force - (answer)Pound (lb)
Formula for Force - (answer)Pressure ÷ Area
Unit of Work - (answer)in-lb or ft-lb
Formula for Work - (answer)Force x Distance
Unit of Power - (answer)ft-lb/min
Formula for Power - (answer)= Work ÷ Time
or (Force x Distance) ÷ Time
Formula for Mechanical Horsepower - (answer)= Power ÷ 33,000 ft-lb/min
Fahrenheit to Celsius - (answer)°C = (°F - 32) ÷ 1.8
,DC Boiler Exam Prep 2023(Formulas and constants used for the DC 3rd class boiler
exam)Verified 100%
Celsius to Fahrenheit - (answer)°F = (1.8 x °C) - 32
Fahrenheit to Rankine - (answer)°R = °F + 460
Celsius to Kelvin - (answer)K = °C +273.15
Charles' First Law - (answer)Volume1 / Pressure1 = Volume2 / Pressure2
Charles' Second Law - (answer)Pressure1 / Temperature1 = Pressure2 / Temperature2
Boyle's Law - (answer)Pressure1 x Volume1 = Pressure2 x Volume2
General Gas Law - (answer)(Pres1 x Vol1)/ Temp1 = (Pres2 x Vol2)/Temp2
Formula for Levers - (answer)Resistance x DistanceR = Effort x DistanceE
Formula for Inclined Planes - (answer)Force x Length = Resistance x Height
Formula for Wheel & Axel - (answer)Force x DistanceF = Resistance x DistanceR
Torque - (answer)Force x Radius
Safe Working Pressure of a Riveted Boiler (SWP) - (answer)(Area of Staybolt x Stress Constant of
Staybolt) ÷ Area Covered by Staybolt or = (a x C) ÷ A
Area Covered by Staybolt - (answer)= Pitch x Pitch
, DC Boiler Exam Prep 2023(Formulas and constants used for the DC 3rd class boiler
exam)Verified 100%
Longitudinal Stress - (answer)(P x D x L) / 2t
P = Pressure
D = Diameter
L = Length
t = thickness of steel
Boiler Heating Surface (tubes) = - (answer)= C x L x #
C = Circumference of tubes
L = Length of tubes
# = Number of tubes
HS = π x Diameter x Length x Number of Tubes
Watts per Boiler Horsepower - (answer)746 Watts
Horsepower formula - (answer)= ft-lb/min ÷ 33000 ft-lb/min
ft-lb formula for a pump - (answer)= gpm x 8.33 x head (ft)
Factor of Evaporation (FE) = - (answer)= [Hs - (tfw-32)] ÷ 970.3
Hs = Enthalpy of steam
tfw = temperature of feed water
Latent Heat of Vaporization for Water - (answer)970.3 Btu/lb
Latent Heat of Fusion for Water - (answer)144 Btu/lb
1 Boiler Horsepower = x lbs of steam generator per hour - (answer)34.5 lbs/hr
exam)Verified 100%
Area of a rectangle - (answer)Length x Width
Area of a Circle - (answer).7854 x Diameter²
Volume of a Box - (answer)Length x Width x Height
Volume of a Cylinder - (answer).7854 x Diameter² x Length
Circumference of a Circle - (answer)π x Diameter
Unit of Force - (answer)Pound (lb)
Formula for Force - (answer)Pressure ÷ Area
Unit of Work - (answer)in-lb or ft-lb
Formula for Work - (answer)Force x Distance
Unit of Power - (answer)ft-lb/min
Formula for Power - (answer)= Work ÷ Time
or (Force x Distance) ÷ Time
Formula for Mechanical Horsepower - (answer)= Power ÷ 33,000 ft-lb/min
Fahrenheit to Celsius - (answer)°C = (°F - 32) ÷ 1.8
,DC Boiler Exam Prep 2023(Formulas and constants used for the DC 3rd class boiler
exam)Verified 100%
Celsius to Fahrenheit - (answer)°F = (1.8 x °C) - 32
Fahrenheit to Rankine - (answer)°R = °F + 460
Celsius to Kelvin - (answer)K = °C +273.15
Charles' First Law - (answer)Volume1 / Pressure1 = Volume2 / Pressure2
Charles' Second Law - (answer)Pressure1 / Temperature1 = Pressure2 / Temperature2
Boyle's Law - (answer)Pressure1 x Volume1 = Pressure2 x Volume2
General Gas Law - (answer)(Pres1 x Vol1)/ Temp1 = (Pres2 x Vol2)/Temp2
Formula for Levers - (answer)Resistance x DistanceR = Effort x DistanceE
Formula for Inclined Planes - (answer)Force x Length = Resistance x Height
Formula for Wheel & Axel - (answer)Force x DistanceF = Resistance x DistanceR
Torque - (answer)Force x Radius
Safe Working Pressure of a Riveted Boiler (SWP) - (answer)(Area of Staybolt x Stress Constant of
Staybolt) ÷ Area Covered by Staybolt or = (a x C) ÷ A
Area Covered by Staybolt - (answer)= Pitch x Pitch
, DC Boiler Exam Prep 2023(Formulas and constants used for the DC 3rd class boiler
exam)Verified 100%
Longitudinal Stress - (answer)(P x D x L) / 2t
P = Pressure
D = Diameter
L = Length
t = thickness of steel
Boiler Heating Surface (tubes) = - (answer)= C x L x #
C = Circumference of tubes
L = Length of tubes
# = Number of tubes
HS = π x Diameter x Length x Number of Tubes
Watts per Boiler Horsepower - (answer)746 Watts
Horsepower formula - (answer)= ft-lb/min ÷ 33000 ft-lb/min
ft-lb formula for a pump - (answer)= gpm x 8.33 x head (ft)
Factor of Evaporation (FE) = - (answer)= [Hs - (tfw-32)] ÷ 970.3
Hs = Enthalpy of steam
tfw = temperature of feed water
Latent Heat of Vaporization for Water - (answer)970.3 Btu/lb
Latent Heat of Fusion for Water - (answer)144 Btu/lb
1 Boiler Horsepower = x lbs of steam generator per hour - (answer)34.5 lbs/hr
