Dry riser

A dry riser is a normally empty pipe that can be externally connected by firefighters to a pressurised water source. It is a vertical pipe intended to distribute water to multiple levels of a building or structure as a component of the fire suppression systems.

Dry riser inlet at the ground floor of flats in Singapore

Dry riser inlet box at Park Street Car Park in Cambridge, United Kingdom

Most buildings have a "wet riser" or "wet standpipe" system where the pipes are kept full of water for manual or automatic fire fighting operations. Dry risers are used when the water pressure of a building wouldn't be enough for fire suppression and in unheated buildings where the pipes could freeze. In the UK, dry risers must allow fire engine access within 18 m of the dry riser inlet box.[1] Dry risers in occupied buildings must be within a fire-resistant shaft, usually one of a building's fire escape staircase enclosures. The riser is also where the gauges, valves, and alarm devices are located.

Depending on regional nomenclature, the term "dry riser" may refer to a standpipe, intended to provide water to fire hose connections, or a vertical main pipe in an automatic dry pipe fire sprinkler system. A dry standpipe has an external fire department connection at ground level, such as a Storz coupling, through which water can be pumped from the fire engine pump to the fire hose attachments on each floor. A dry pipe fire sprinkler system is a network of pipes connected to fixed sprinklers inside a building, which is full of air until one of the sprinklers is triggered.