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A standpipe or riser is a type of rigid water piping which is built into multi-story buildings in a vertical position, or into bridges in a horizontal position, to which fire hoses can be connected, allowing manual application of water to the fire. Within the context of a building or bridge, a standpipe serves the same purpose as a fire hydrant. NFPA 14 - Standard for the Installation of Standpipe and Hose Systems regulates the design of standpipe system in the United States.<ref name="nfpa 14"/> Some standpipe systems are combined with fire sprinkler systems, using common pipes to supply both the sprinklers and hose connections.
Types of standpipe systemsEdit
Fire standpipes have two broad types: "Wet" and "Dry". The terms describe their state during normal, non-firefighting situations.
Dry standpipeEdit
Dry standpipe systems do not contain water in the piping during normal, non-firefighting situations. Water is only introduced when needed for firefighting purposes.
Manual Dry Standpipe System - A standpipe system that is not connected to a water supply and requires water to be pumped into the system via a fire department connection (FDC), often by a fire truck.<ref name="nfpa 14"/>
Semiautomatic Dry Standpipe System - A standpipe system that is connected to a water supply and capable of supplying the water at any time, but requires the manual activation of a valve or other control to introduce the water into the system.<ref name="nfpa 14"/>
Automatic Dry Standpipe System - A standpipe system that is connected to a water supply and capable of supplying the water at any time, that is kept under air pressure, so that upon the opening of a hose supply connection valve, water is drawn into the system via a dry pipe valve.Template:Efn <ref name="nfpa 14"/>
Wet standpipeEdit
Wet standpipe systems contain water at all times.
Manual Wet Standpipe System - A standpipe system that contains water, but requires additional water to be pumped into the system via a fire department connection (FDC), often by a fire truck.<ref name="nfpa 14"/>
Automatic Wet Standpipe System - A standpipe system that is connected to a water supply and capable of supplying the water without any action except opening a hose supply connection valve.<ref name="nfpa 14"/>
Wet standpipe systems are often more complex and expensive to both install and maintain due to the presence of water always being in the system, and the need to supply water a specific pressures which may require the use of pumps.<ref name="ifsta 2011"/>
Standpipe classesEdit
Under NFPA 14, standpipes designs are classified as Class I, II, or III based on intended user, size of hose connections and design pressure.<ref name="ifsta 2011">Template:Cite book</ref><ref name="nfpa 14">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
Class IEdit
Class I standpipe systems are intended for use by firefighters, and consists of Template:Convert hose connections to accommodate the fire hoses used by fire departments. Class I systems must be constructed with Template:Convert pipe, and at least Template:Convert in buildings with fire sprinkler systems to ensure adequate water supply during usage, and water pressure at the hose connection must be between Template:Convert.<ref name="nfpa 14"/>
Class IIEdit
Class II systems are intended for use by building occupants, such as employees, residents or members of the public, and include a hose station containing a Template:Convert fire hose and nozzle pre-connected to the standpipe.<ref name="nfpa 14"/> Class II systems have become less common in recent years, but are still found in buildings.<ref name="ifsta 2011"/> Template:Convert hose no longer than Template:Convert must be installed and ready for firefighting usage in Class II systems.<ref name="nfpa 14"/>
Class II systems are required to be 'wet', except in regions subject to freezing temperatures and on-site personnel, such as an industrial fire brigade, are trained how to activate the system without assistance from the local fire department.<ref name="nfpa 14"/> Pipes supplying hose stations on Class II systems do not have a specified size, and must be calculated based on the needs of the specific system. Water pressure at hose connections must be between Template:Convert.<ref name="nfpa 14"/>
Class IIIEdit
Class III systems are designed to include both Class I and Class II: An occupant operated Template:Convert fire hose and Template:Convert hose connections for firefighters. The system must be able to operate both the occupant hose and a firefighter's hose simultaneously, and comply with the design standards for both systems.<ref name="ifsta 2011"/><ref name="nfpa 14"/>
Location of standpipesEdit
NFPA 14 requires that Class I and III standpipe hose connections be found at the main floor landing of exit stairwaysTemplate:Efn, along exit routes, both sides of fire doors.<ref name="nfpa 14"/> Hose connections on standpipes also cannot be blocked by stairway doors, when open or closed positions.<ref name="nfpa 14"/>
Class II systems must be located on each floor, with hose stations distributed so an occupant is always within Template:Convert of a hose station.<ref name="nfpa 14"/>
Standpipe systems are required by the International Building Code (IBC) in the following situations:<ref name="ibc 2021">{{#invoke:citation/CS1|citation |CitationClass=web }} - Chapter 9 - Fire Protection and Life Safety Systems - Section 905.3 - Required Installations</ref>
- Structures that are 4 or more floors above ground level, or over Template:Convert above or below ground level.
- Structures allowed to contain more than 1,000 people.
- Shopping malls, both open and enclosed.
- Structures with stages larger than Template:Convert
- Underground structures
- Structures with rooftop heliports
- Marinas and boatyards
- Structures with landscaped roofs
AdvantagesEdit
Laying a firehose up a stairwell takes time, and this time is saved by having fixed hose outlets already in place. There is also a tendency for heavy wet hoses to slide downward when placed on an incline (such as the incline seen in a stairwell), whereas standpipes do not move. The use of standpipes keeps stairwells clear and is safer for exiting occupants.
Standpipes go in a direct up and down direction rather than looping around the stairwell, greatly reducing the length and thus the loss of water pressure due to friction loss. Additionally, standpipes are rigid and do not kink, which can occur when a firehose is improperly laid on a stairwell.
Standpipe systems also provide a level of redundancy, should the main water distribution system within a building fail or be otherwise compromised by a fire or explosion.
DisadvantagesEdit
Standpipes are not fail-safe systems and there have been many instances where fire operations have been compromised by standpipe systems which were damaged or otherwise not working properly. During the One Meridian Plaza fire, firefighters were incapable of fighting the fire due to pressure reduction valves being improperly set too low, preventing fire hoses from operating correctly for the duration of the fire.<ref name="one meridian"/> The fire's upward spread ultimately stopped when it reached a floor with working fire sprinklers, and burned itself out. Three Philadelphia firefighters died in the fire and the structure was a total loss and demolished years later.<ref name="one meridian">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Two New York City firefighters died in the 2007 Deutsche Bank Building fire during its demolition. A factor that hampered extinguishing the fire was the standpipe system had been rendered inoperable during demolition and incorrect information from demolition workers regarding the status of the standpipe.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Firefighters must take precautions to flush the standpipe before use to clear out debris that could obstruct nozzles and hoses and ensure that water is available.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
The One Meridian Plaza fire also highlighted a flaw in standpipe systems which are fed water via a fire department connection; falling debris can damage or completely sever hoses supplying standpipes.<ref name="one meridian"/>
See alsoEdit
NotesEdit
ReferencesEdit
- Essentials of Fire Fighting, Fourth Edition, copyright 1998 by the Board of Regents, Oklahoma State University