Fire Hydrant Connection Sizes

Mismatched threading was a major contributor to at least two historic fires.

Fire hydrant connection sizes. Two 2 1 2 inch 65 mm side outlets and a single 4 1 2 inch 115 mm or 6 inch 150 mm pumper outlet. This is a connection on the exterior of a commercial building where a responding fire department can attach a fire hose and pump water into the building s stand pipe system supplementing the water pressure to the buidling s sprinkler system. 100 mm but not less than the largest riser. Pipe size shall be a minimum of 4 in.

Fire hose nozzles have female inlets that connect to male ended fire hoses. Fdc stands for fire department connection. Dry hydrants are pipes connected to unpressurized water sources like lakes or ponds the choice of male or female threads varies from place to place. Harrington integral hydrant storz permits firefighters to connect fire hose to your hydrant in seconds.

Pipe size shall be a minimum of 6 in. 100 mm for fire engine connections. 19 mm nominal diameter fitted with garden hose couplings. Fire hose and hydrant adapters are fittings that securely connect fire hoses to nozzles hydrants fire trucks and other water sources.

The flange at the base of the hydrant is the point of connection for the hydrant to the rest of the barrel. Hydrants have 5 1 4 bonnets upper barrels safety flanges and lower barrels and are marked 5 1 4 even though the main valve opening is 4 1 2. The size and number of the outlets serve as one limit to the. 4 1 2 m v o.

All size fittings available. Fire hydrants have male threaded outlets or nozzles. Seat ring removeable without removing lower barrel. X 4 tpi threads per inch.

The great baltimore fire of 1904 which destroyed more than 1 500 buildings in baltimore md and the 1991 oakland hills fire where incompatible hose and fire hydrant couplings delayed a fight against an oakland ca blaze that killed 25 people. Harrington s is widely regarded as the most efficient available. Dia thds inch ns national standard follows nst also nh 2 5 7 5 4 5 4 austin tx ns 4 6 charlotte nc ns 4 6 chicago il 4 5. A 1 1 1 some fire fighting organizations use small hose less than 3 4 in.

19 mm through 8 in. 1 1 1 this standard gives the performance and requirements for new fire hose couplings and adapters with nominal sizes from 3 4 in. 200 mm and the specifications for the screw thread connections on those couplings and adapters. A traditional dry barrel fire hydrant contains three outlets.

For hydraulically calculated systems the pipe size shall be permitted to be less than 4 in. Connection takes just 1 4 turn to connect or disconnect. Fire hydrant having barrel thread dimensions of 8 250 o d. 150 mm for fire boat connections.