In the context of building design and fire protection systems, a riser and a standpipe are both vertical pipes used to deliver water to different levels of a building. However, there are some differences between the two.
A riser is a vertical pipe or shaft that carries water from a supply source, such as a pump or a tank, to various levels of a building. Riser pipes are typically used to supply water to the sprinkler systems, fire hydrants, and fire hose cabinets on each floor of a building. Risers are typically located within the building and are usually made of steel or other materials that can withstand high pressure.
On the other hand, a standpipe is a vertical pipe that is designed to provide water for fire-fighting purposes. Standpipes are usually located in stairwells or other dedicated spaces within the building and are equipped with fire hose connections on each floor. Firefighters can connect their hoses to these standpipes to access water and fight fires on different levels of the building.
In summary, a riser is a pipe used to distribute water within a building, while a standpipe is a pipe designed specifically for fire-fighting purposes