Three-Inch Hose : A common hose, about 3 in. in diameter, that is capable of delivering 40 percent more water than 2 1/2 in. hose, at the same friction loss
Ralph W. Burklin & Robert G. Purington, Fire Terms: A Guide to Their Meaning and Use, National Protection Association, Boston, MA 1980 USA. (Guide: Meaning and Use, Nat Prot Association Fr Srvc - Amer) {457}