Circle Conversion:
Circumference = 3.1416 x diameter
Area of a circle = 3.1416 x radius x radius
Temperature Conversion:     (C=Celsius, F=Fahrenheit)
Celsius = 5/9 x (F-32)
Fahrenheit = 9/5 x C + 32
Surveyor Conversion:
1 mile = 80 chains = 320 rods
1 mile = 1,760 yards = 5,280 feet
1 chain = 4 rods = 22 yards = 66 feet = 100 links
1 rod = 5.5 yards = 16.5 feet
1 link - 7.92 inches
Power Conversion:
Horsepower =	Q x H 3960 x E	Where: Q = System flow rate (gpm) H = Total head in feet (multiply psi by 2.31 to convert to ft.) E = Operating efficiency of pump (in decimal)
Pump Efficiency =	Q X H 3,960 x BHP to E
Miscellaneous Rules:
450 gpm x 60 min = 1 acre-inch of water
Doubling pipe diameter quadruples capacity