What type of hydrant is designed to prevent freezing of water inside its barrel?

The dry-barrel hydrant is designed specifically for colder climates where the risk of freezing is a concern. In this type of hydrant, the water is stored below the frost line within the barrel, and the hydrant does not retain water in the barrel when the hydrant is not in use. Instead, the water supply is only directed to the hydrant when it is opened for use, which prevents any standing water in the upper portion from freezing during cold weather.

In contrast, wet-barrel hydrants contain water in the upper part of the barrel under normal operating conditions, which makes them unsuitable for freezing temperatures as the water can freeze and cause damage. Static and residual hydrants are terms that refer to different aspects of water pressure measurement and do not pertain to the design of hydrants concerning freezing issues.