Loop 02 : (1) A water main laid out in a circle so that water can be supplied to any point from two directions, thus reducing friction loss in the main. (2) A more or less circular figure formed by a rope that curves back to cross itself
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}