Riser 02 : (1) A vertical supply pipe in a sprinkler or standpipe system. (2) Any vertical pipe. (3) The vertical portion of a stairway between the treads
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}