(Couvillon, 2006, p33)
If a length of hose is of a diameter of less than 2 1/ 2 inch. We can determine its equivalent length in 2 inch hose by dividing the length of the hose by a conversion factor. (Sylvia and Casey, 2002, p 112)
The larger diameter hose length is divided by the factor to find the equivalent length of 21/2 inch hose, to change other sizes of hose to 2 1/2 inch hose, conversion rates are used. The conversion factors for changing to 2 inch hose is given below (Casey, 1970, p256).