What are the two main types of modern fire hydrants?

• A. Wet and semi-dry
• B. Dry and semi-dry
• C. Wet and dry barrel
• D. Wet and pressure

Answer: (C)

Two main types of modern fire hydrants are defined by where the water sits and where the valve is located. Wet-barrel hydrants have a water-filled barrel with the valve inside the barrel itself, so when you open an outlet, water is immediately available. This setup works best in warmer climates where freezing isn’t a concern and it provides the quickest flow.

Dry-barrel hydrants keep the barrel dry and place the valve underground in the supply line. The above-ground portion remains dry until the hydrant is opened; water then flows into the outlets from the underground line, and drains remove water after use to prevent freezing. This design is favored in areas that experience freezing temperatures. Other terms like semi-dry describe variants, but the two primary modern classifications are wet-barrel and dry-barrel.