Commercial Fire Protection Service
Fire Department Connections (FDC)
An FDC lets the fire department pump supplemental water into a building’s standpipe or sprinkler system from the exterior.
Overview
A Fire Department Connection, often called a siamese connection, is an exterior fitting that allows the fire department to pump additional water into a building’s standpipe or sprinkler system, supplementing or backing up the building’s own water supply during a fire response.
Because an FDC is only useful in an emergency if it can actually be found and connected quickly, code places significant emphasis on its visibility, accessibility, and correct signage.
How an FDC Works
A fire engine connects its hose to the FDC’s inlet fitting and pumps water into the building’s internal piping, boosting pressure and flow beyond what the building’s own supply, or fire pump if equipped, can provide on its own.
Placement & Visibility Requirements
Code requires FDCs to remain visible, accessible, and unobstructed from the street or fire apparatus access route, with clear signage identifying which system, standpipe, sprinkler, or both, the connection serves.
FDC Testing & Maintenance
Periodic inspection under NFPA 25 checks for physical damage, caps that are painted shut or missing, and worn gaskets or swivels that could prevent a fast, reliable connection during an actual response.
Frequently Asked Questions
Why do some buildings have more than one FDC?
Larger buildings, or those with both a sprinkler system and a separate standpipe system, often have multiple FDCs so the fire department can supply each system independently or approach from more than one side of the building.
What does the signage on an FDC mean?
Signage identifies which system the connection feeds, such as “sprinkler,” “standpipe,” or “combined,” helping responding crews connect to the correct inlet quickly.
Can an FDC be blocked by landscaping or parking?
No. Code requires FDCs to remain visible and accessible at all times, and property owners are responsible for keeping landscaping, snow, vehicles, or stored materials from obstructing them.
Get FDC Installation, Testing, or Repair
Connect with a contractor to install, inspect, or repair your Fire Department Connection.