NOTE This standard covers fire department connections (FDCs): the listed assemblies that allow fire department pumper apparatus to inject supplemental water into a building's automatic sprinkler, standpipe, or combination fire protection system. (1.1)

NOTE The covered assembly includes the FDC body, inlets (2½ in. National Standard Thread, Storz large-diameter, or combination), swing clappers, the integral or in-riser check valve, the automatic ball drip drain, the pipe connection to the system riser, protective inlet caps, and the required identification signage. (1.2)

NOTE FDC configurations covered are wall-mounted exposed (Siamese), wall-mounted recessed (flush box), freestanding post-type, and sidewalk box assemblies on commercial, institutional, industrial, and multi-family residential buildings of all sizes. (1.3)

NOTE This standard applies to new construction and to additions or retrofits of existing fire protection systems where a new or relocated FDC is required by code or by AHJ directive. (1.4)

NOTE The fire department connection is the supply interface to the protected system, not the system itself. (1.5)

NOTE The system piping, risers, control valves, and hydraulic design that the FDC feeds are governed by the system standards: Wet Pipe Fire Sprinkler Systems, Dry Pipe Fire Sprinkler Systems, Pre Action And Deluge Sprinkler Systems, and Standpipe Systems. This standard ends at the listed check valve that separates the FDC from the system riser. (1.6)

NOTE The following are excluded from this standard and are governed elsewhere. (1.7)

NOTE Where the AHJ adopts a different edition or imposes a local amendment, the AHJ-adopted requirement shall govern. (2.3)

NOTE IFC Section 912 grants the AHJ final authority over FDC location, and that authority is exercised more aggressively here than for most fire protection components. A location that is reasonable on paper can be rejected by the fire marshal if the apparatus cannot reach it, if it is screened from view, or if it conflicts with the department's standard approach. Because the FDC is fed by underground piping, a late location change forces costly rerouting. The fire marshal's pre-construction meeting is the single most effective step for avoiding location-related RFIs. (4.3)

NOTE Standard rough or polished brass is appropriate for ordinary atmospheric exposure. In coastal, marine, or chemically aggressive industrial environments, chloride and airborne contaminants pit and dezincify brass, seizing caps and clappers; a stainless steel body is specified for those exposures. The exposure assessment is made for the specific site, not assumed from the building type. (5.2)

NOTE Water trapped between the system check valve and the inlet caps has no path to drain on its own. In a freeze-prone location it freezes, expands, and can crack the FDC body or unseat the clappers. NFPA 13 Section 8.17.2.6 requires an automatic drip valve for exposed or minimally heated FDCs. The drip discharges this trapped water continuously to a safe point. (5.4)

NOTE The four common types serve different site conditions. The wall-mounted exposed Siamese is the default and the easiest to operate. The recessed flush type hides the body in a wall box for architectural integration and is required by some AHJs and architects. The freestanding post-type is used when no suitable wall location exists or when the AHJ wants the connection remote from the building. The sidewalk box is used where the FDC must sit at or below a paved surface. (6.2)

NOTE IFC Section 912.2.1 requires the FDC to be in a visible, identifiable location that responding apparatus can reach. Section 912.2.2 governs height, and Section 912.3 governs the unobstructed clearance around the connection. These are mandatory dimensional requirements, not preferences. (6.4)

NOTE FDC mounting height frequently generates RFIs when finished grade changes late in design. (6.5)

NOTE The 24 in. to 60 in. window is measured to finished grade, not to the slab or to the pipe penetration. When site grading is revised after the FDC elevation is set, the as-built inlet height can fall outside the code window. Setting the inlet centerline against the final grading plan, and rechecking it when grading changes, prevents the rework. (6.6)

NOTE Defaulting to "two 2½-inch inlets" regardless of demand is one of the most common FDC errors. The inlet count is a hydraulic requirement. For sprinkler systems, NFPA 13 sets the minimum on the basis of riser size. For standpipe and combination systems, NFPA 14 Section 7.12.3 requires one 2½-inch inlet for each 250 gpm of system demand, so a 1,000 gpm standpipe system requires four inlets, not two. (7.2)

NOTE National Standard Thread (NST/NH) per ASME B1.20.7 is the common default, but it is not universal. Several major cities - Chicago, Pittsburgh, New York, and others - use proprietary local thread forms, and a number of departments are standardizing on Storz large-diameter connections. Specifying NST without written confirmation from the AHJ is among the most common and most expensive FDC errors, because a mismatched FDC body must be replaced after the wall is built. Always obtain the thread standard in writing before ordering. (7.4)

NOTE Storz large-diameter inlets are increasingly required where the department runs large-diameter hose. (7.5)

NOTE A single Storz inlet replaces the twin 2½-inch arrangement for departments equipped with large-diameter hose (LDH). The 2023 NFPA guidance rates a 4 in. Storz inlet at 500 gpm and a 5 in. Storz inlet at 750 gpm. A Storz inlet is genderless and connects faster than threaded inlets, which is why adoption is growing. Where the existing FDC is threaded, a listed thread-to-Storz swivel adapter can be added, but a purpose-built Storz body is preferred on new work. (7.6)

NOTE The body is the cast structure that carries the inlets and joins them to the system pipe connection. Each inlet contains a swing clapper that opens under pumper pressure and closes to retain system water when the inlet is not in use. UL 405 listing covers the construction, the clapper action, and the pressure rating of the complete assembly. (8.2)

NOTE The check valve prevents system water - and any contaminant the system may have picked up - from flowing back into the FDC and out to the street supply. NFPA 13 requires it, and it is sometimes omitted on simple systems, which is a code violation and a cross-connection hazard. The check valve may be built into the FDC body as a clapper assembly or provided as a separate listed check valve in the riser; either arrangement satisfies the requirement when listed for the service. (8.4)

NOTE NFPA 13 sets a 4 in. pipe connection from the FDC to the riser as the default for most sprinkler systems. High-demand combination systems require a larger connection sized by the hydraulic calculation. The connection is most commonly a female NPT threaded inlet on the FDC body; a flanged connection is used on larger or higher-pressure work. (9.2)

NOTE Brass caps with chains are the traditional choice and resist vandalism better than plastic. Plastic break-away caps are inexpensive and visibly indicate tampering. Locking security caps deter theft of the brass body and prevent debris insertion in vandalism-prone areas, but they require a key carried by the responding department. (10.2)

NOTE A locking cap that the responding company cannot open quickly is an operational hazard - it can delay a supplemental supply at the moment it is needed. Locking caps are only acceptable where the fire department carries the matching key or where a standardized regional key system is in use. The arrangement is confirmed with the department, not assumed. (10.4)

NOTE NFPA 13 requires a sign with raised or engraved letters not less than 1 in. tall identifying the served system. Adhesive labels are not compliant and are routinely rejected by the AHJ. The legend names the system type so that the responding company connects to the correct supply, which matters where a site has more than one FDC. (11.2)

NOTE Where the system requires more than 150 psi at the FDC to meet demand, the responding pump operator must know the target pressure to charge the connection correctly. The pressure demand is added to the identification sign as a note so the information is at the connection rather than buried in the record drawings. (11.4)

NOTE NFPA 14 requires an additional sign on a combination or shared FDC that lists all of the buildings or zones the connection feeds. Without it, a responding company cannot tell from the FDC which areas will be supplied, and a connection meant for one zone can be misapplied to another. (11.6)

NOTE UL 405 requires a hydrostatic proof test of the assembly and verification of clapper operation. This is a production test of the listed product, distinct from the field acceptance test. (12.2)

NOTE Field acceptance confirms the as-installed connection is sound and operable. Caps are removed, the inlets and clappers are inspected, and each clapper is operated by hand to confirm it swings freely and reseats. The FDC piping is included in the hydrostatic test of the connected system. NFPA 25 governs the inspection and test frequency for the life of the installation; the FDC is inspected at least annually thereafter. (12.4)

NOTE The mounting position, the pipe routing to the riser, and the discharge point of the ball drip are spatial decisions that cannot be reduced to a datasheet field; they are coordinated on the drawings. (13.2)

NOTE The inlet threads and clapper seats are the working surfaces of the connection; a nicked thread or a dented seat can prevent a tight hose coupling or a proper clapper reseat. Protective caps and plugs stay in place until installation, and the assemblies are kept off the ground and dry. (14.2)

NOTE Caps and chains are the parts most often lost to theft or vandalism, and clapper rubbers wear over time. A small spare stock keeps the connection serviceable. (16.2)