These fire hydrants are used in climates that are expected to have freezing temperatures.

These fire hydrants are used in climates that are expected to have freezing temperatures.

• A. Dry-barrel hydrants
• B. Wet-barrel hydrants
• C. Convertible hydrants
• D. Wet-hybrid hydrants

Answer: (A)

In climates that freeze, the main point is to keep water from sitting in parts of the hydrant that can freeze. A dry-barrel hydrant does exactly that by placing the main valve underground, well below the frost line, while the barrel on the surface stays dry when not in use. Water is drawn up only when needed and then drains back down into the main after use, leaving the barrel dry and resistant to freezing. Wet-barrel hydrants, by contrast, have water-filled barrels above ground, so in freezing temperatures the water can freeze and impede operation. Convertible hydrants can be switched to dry operation, but that requires draining and is not as straightforward in freezing conditions. Wet-hybrid designs mix features but still carry more risk of freezing compared to a true dry-barrel setup. So, the hydrants chosen for locations expected to experience freezing temperatures are dry-barrel hydrants.

In climates that freeze, the main point is to keep water from sitting in parts of the hydrant that can freeze. A dry-barrel hydrant does exactly that by placing the main valve underground, well below the frost line, while the barrel on the surface stays dry when not in use. Water is drawn up only when needed and then drains back down into the main after use, leaving the barrel dry and resistant to freezing.

Wet-barrel hydrants, by contrast, have water-filled barrels above ground, so in freezing temperatures the water can freeze and impede operation. Convertible hydrants can be switched to dry operation, but that requires draining and is not as straightforward in freezing conditions. Wet-hybrid designs mix features but still carry more risk of freezing compared to a true dry-barrel setup.

So, the hydrants chosen for locations expected to experience freezing temperatures are dry-barrel hydrants.