This standard covers flexible sprinkler hose with fittings intended for use with fire sprinklers in installations requiring a flexible attachment to the sprinkler system piping such as clean rooms, suspended ceilings, and exhaust ducts. Revised effective November 10, 2006. The products covered by this standard are intended for use in sprinkler systems installed in accordance with the Standard for Installation of Sprinkler Systems, NFPA 13; Standard for the Installation of Sprinkler Systems in Residential Occupancies Up to Four Stories in Height, NFPA 13R; and Standard for the Installation of Sprinkler Systems in One- and Two-Family Dwellings and Mobile Homes, NFPA 13D