Hydrant types designed to mitigate freezing will typically have which feature?

Hydrants designed to mitigate freezing often feature a dry-barrel composition. This design helps prevent water from being trapped in the hydrant's barrel, which could freeze in cold conditions. In a dry-barrel hydrant, the water supply is contained below the frost line, and only the nozzle area is filled with water when the hydrant is in use. When the hydrant is shut off, the water drains back down into the underground system, leaving the barrel dry. This minimizes the risk of freezing and allows the hydrant to function effectively even in low temperatures.

In contrast, obstacles such as an insulated casing, while beneficial in some applications, do not provide the same level of freeze prevention as the dry-barrel design. Likewise, retractable heads do not inherently address the issue of freezing and are not a common feature specifically aimed at mitigating freezing in hydrants. A spout for drainage is also not as effective in ensuring that the hydrant remains ice-free, as this doesn't prevent water from being retained in the text of the hydrant itself without an appropriate structural design.