Wye Appliance

What Is Wye Appliance?

A wye appliance is a gated hose fitting featuring one large inlet (e.g., 2½-inch) and two smaller outlets (e.g., 1½-inch) equipped with quarter-turn ball valves, used to split a single supply line into two attack lines.

Why Wye Appliance Matters on the Fireground

Using a gated wye allows a single 2½-inch supply line stretched to an upper floor or long driveway to feed two separate 1¾-inch attack lines, reducing hose weight and setup time.

Relevant NFPA Standards

• NFPA 1960: Standard for Fire Hose Connections, Spray Nozzles, Manufacturer's Design of Fire Department Ground Ladders, Fire Hose, and Powered Rescue Tools
• NFPA 1930: Standard on Fire and Emergency Service Use of Thermal Imagers, Two-Way Portable RF Voice Communication Devices, Ground Ladders, Rescue Tools, Fire Hose, and Fire Hose Appliances

Field Procedures & Tactical Steps

1. Connect wye appliance inlet to 2½-inch supply line.
2. Attach 1¾-inch attack lines to the two gated outlets.
3. Verify gate valves are closed before charging supply line.
4. Open individual gate valves slowly when attack teams request water.
5. Add 10 PSI appliance friction loss to pump calculations when flowing over 350 GPM.

Common Context & Application

Deployed at courtyard entries, high-rise stairwells, long driveways, and wildland hose lays.

Frequently Asked Questions about Wye Appliance