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

Fire

Fire is the rapid oxidation of a material in the chemical process of combustion, releasing heat, light, and various reaction products. Slower oxidative processes like rusting or digestion are not included by this definition....

 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. (In the UK they are controlled by the Building (Minimum Standards) Regulations 2000. Dry Risers in occupied buildings have to be within a fire resistant shaft, usually one of a building's fire escape staircase enclosures.)
Depending on regional nomenclature, this may refer to a standpipe, intended to provide water to hose connections, or could refer to a vertical main pipe in an automatic dry pipe fire sprinkler system.

A dry standpipe includes a fire department connection which is an external access point at ground level through which water

Water

Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...

 can be pumped from the fire department's fire engine

Fire apparatus

A fire apparatus, fire engine, fire truck, or fire appliance is a vehicle designed to assist in fighting fires by transporting firefighters to the scene and providing them with access to the fire, along with water or other equipment...

 pump to firefighters' hose attachments on each floor.

Dry Pipe Fire Sprinkler System

A dry pipe fire sprinkler system is one in which pipes are filled with pressurized air, rather than water. This air holds a remote valve, known as a dry pipe valve, in a closed position. Located in a heated space, the dry-pipe valve prevents water from entering the pipe until a fire causes one or more sprinklers to operate. Once this happens, the air escapes and the dry pipe valve releases. Water then enters the pipe, flowing through open sprinklers onto the fire.

See also

• Fire fighting
  Fire fighting
  Firefighting is the act of extinguishing fires. A firefighter fights fires to prevent loss of life, and/or destruction of property and the environment...
  
  
• Fire sprinkler
  Fire sprinkler
  A fire sprinkler system is an active fire protection measure, consisting of a water supply system, providing adequate pressure and flowrate to a water distribution piping system, onto which fire sprinklers are connected...
  
  
• Fire sprinkler system
• Dry Standpipe
• Siamese connection
  Siamese connection
  In fire protection engineering, a Siamese connection is a pipe fitting that allows two fire hoses to be connected to a single standpipe riser at the same general location. It is so-called due to the visual allegory to Siamese twins.-References:...