DC Boiler Exam Prep 2023 (Formulas and constants used for the DC 3rd class
boiler exam)
1. Area of a rectangle - ☑☑☑Length x Width
2. Area of a Circle - ☑☑☑.7854 x Diameter²
3. Volume of a Box - ☑☑☑Length x Width x Height
4. Volume of a Cylinder - ☑☑☑.7854 x Diameter² x Length
5. Circumference of a Circle - ☑☑☑π x Diameter
6. Unit of Force - ☑☑☑Pound (lb)
7. Formula for Force - ☑☑☑Pressure ÷ Area
8. Unit of Work - ☑☑☑in-lb or -lb
9. Formula for Work - ☑☑☑Force x Distance
10.Unit of Power - ☑☑☑ -lb/min
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,11.Formula for Power - ☑☑☑= Work ÷ Time
12.or (Force x Distance) ÷ Time
13.Formula for Mechanical Horsepower - ☑☑☑= Power ÷ 33,000 -lb/min
14.Fahrenheit to Celsius - ☑☑☑°C = (°F - 32) ÷ 1.8
15.Celsius to Fahrenheit - ☑☑☑°F = (1.8 x °C) - 32
16.Fahrenheit to Rankine - ☑☑☑°R = °F + 460
17.Celsius to Kelvin - ☑☑☑K = °C +273.15
18.Charles' First Law - ☑☑☑Volume1 / Pressure1 = Volume2 / Pressure2
19.Charles' Second Law - ☑☑☑Pressure1 / Temperature1 = Pressure2 /
Temperature2
20.Boyle's Law - ☑☑☑Pressure1 x Volume1 = Pressure2 x Volume2
21.General Gas Law - ☑☑☑(Pres1 x Vol1)/ Temp1 = (Pres2 x Vol2)/Temp2
22.Formula for Levers - ☑☑☑Resistance x DistanceR = Effort x DistanceE
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, 23.Formula for Inclined Planes - ☑☑☑Force x Length = Resistance x Height
24.Formula for Wheel & Axel - ☑☑☑Force x DistanceF = Resistance x
DistanceR
25.Torque - ☑☑☑Force x Radius
26.Safe Working Pressure of a Riveted Boiler (SWP) - ☑☑☑(Area of
Staybolt x Stress Constant of Staybolt) ÷ Area Covered by Staybolt or = (a x
C) ÷ A
27.Area Covered by Staybolt - ☑☑☑= Pitch x Pitch
28.Longitudinal Stress - ☑☑☑(P x D x L) / 2t
29.P = Pressure
30.D = Diameter
31.L = Length
32.t = thickness of steel
33.Boiler Hea ng Surface (tubes) = - ☑☑☑= C x L x #
34.C = Circumference of tubes
35.L = Length of tubes
36.# = Number of tubes
37.HS = π x Diameter x Length x Number of Tubes
38.Wa s per Boiler Horsepower - ☑☑☑746 Wa s
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boiler exam)
1. Area of a rectangle - ☑☑☑Length x Width
2. Area of a Circle - ☑☑☑.7854 x Diameter²
3. Volume of a Box - ☑☑☑Length x Width x Height
4. Volume of a Cylinder - ☑☑☑.7854 x Diameter² x Length
5. Circumference of a Circle - ☑☑☑π x Diameter
6. Unit of Force - ☑☑☑Pound (lb)
7. Formula for Force - ☑☑☑Pressure ÷ Area
8. Unit of Work - ☑☑☑in-lb or -lb
9. Formula for Work - ☑☑☑Force x Distance
10.Unit of Power - ☑☑☑ -lb/min
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,11.Formula for Power - ☑☑☑= Work ÷ Time
12.or (Force x Distance) ÷ Time
13.Formula for Mechanical Horsepower - ☑☑☑= Power ÷ 33,000 -lb/min
14.Fahrenheit to Celsius - ☑☑☑°C = (°F - 32) ÷ 1.8
15.Celsius to Fahrenheit - ☑☑☑°F = (1.8 x °C) - 32
16.Fahrenheit to Rankine - ☑☑☑°R = °F + 460
17.Celsius to Kelvin - ☑☑☑K = °C +273.15
18.Charles' First Law - ☑☑☑Volume1 / Pressure1 = Volume2 / Pressure2
19.Charles' Second Law - ☑☑☑Pressure1 / Temperature1 = Pressure2 /
Temperature2
20.Boyle's Law - ☑☑☑Pressure1 x Volume1 = Pressure2 x Volume2
21.General Gas Law - ☑☑☑(Pres1 x Vol1)/ Temp1 = (Pres2 x Vol2)/Temp2
22.Formula for Levers - ☑☑☑Resistance x DistanceR = Effort x DistanceE
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, 23.Formula for Inclined Planes - ☑☑☑Force x Length = Resistance x Height
24.Formula for Wheel & Axel - ☑☑☑Force x DistanceF = Resistance x
DistanceR
25.Torque - ☑☑☑Force x Radius
26.Safe Working Pressure of a Riveted Boiler (SWP) - ☑☑☑(Area of
Staybolt x Stress Constant of Staybolt) ÷ Area Covered by Staybolt or = (a x
C) ÷ A
27.Area Covered by Staybolt - ☑☑☑= Pitch x Pitch
28.Longitudinal Stress - ☑☑☑(P x D x L) / 2t
29.P = Pressure
30.D = Diameter
31.L = Length
32.t = thickness of steel
33.Boiler Hea ng Surface (tubes) = - ☑☑☑= C x L x #
34.C = Circumference of tubes
35.L = Length of tubes
36.# = Number of tubes
37.HS = π x Diameter x Length x Number of Tubes
38.Wa s per Boiler Horsepower - ☑☑☑746 Wa s
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