Plumbing

Dry Riser

A dry riser is a main vertical pipe intended to distribute water to multiple levels of a building or structure as a component of the fire suppression systems. The pipe is maintained empty of water. The dry riser is the opposite of a "wet riser" or "wet standpipe" system where the pipes are kept full of water for manual or automatic fire fighting operations. Dry risers have to have fire engine access within 18m of the dry riser inlet box.

Wet Riser

A wet riser is a constantly pressurised water pipe supplied by a storage tank with pump, a mains pump or from a mains pressure supply. According to this site: "By a wide margin, wet pipe sprinkler systems are installed more often than all other types of fire sprinkler systems. They also are the most reliable, because they are simple, with the only operating components being the automatic sprinklers and the automatic alarm check valve. An automatic water supply provides water under pressure to the system piping. All of the piping is filled with water. Until sufficient heat is applied, causing one or more sprinklers to fuse (open), the automatic sprinklers prevent the water from being discharged."