# Useful Drycleaning Facts and Factors

General
SOME USEFUL FACTORS FOR YOUR FILES . . .

One micron equals 0.000039 inches
The circumference of a circle is 3.14 X diameter
The area of a circle is 3.14 X (radius)2
The volume of a cylinder is 3.14 X (radius)2 X height
The volume of a cone is 1.05 X (radius)2 X height
The volume of a square tank is length X width X height

With any tank, the sight glass may be calibrated to show the amount of fluid contained by calculating the volume in cubic inches, using 1 inch as the height. When converted to gallons by the following factor, you get the number of gallons per inch on the sight glass and can so mark the tank. A cylindrical tank mounted horizontally can best be calibrated by pumping in a known amount of fluid and marking the level on the sight glass. Volume of such a tank may be calculated when full or half full, but any other level requires advanced math.

To convert cu. inches to gallons, multiply by 0.0043
To convert cu. feet to gallons, multiply by 7.5