CONSTANTS USED FOR THE DC 3RD CLASS BOILER
EXAM) COMPLETE ACTUAL EXAM QUESTIONS AND
CORRECT DETAILED ANSWERS (100% CORRECT
VERIFIED ANSWERS) LATEST UPDATES |ALREADY
GRADED A+ (FULL REVISED EXAM)
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
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
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
1 Boiler Horsepower = x Btu/hr - ANSWER: 33,475 Btu/hr