What type of valve is commonly found in a dry-barrel hydrant?

A dry-barrel hydrant typically uses a gate valve to control the flow of water. The gate valve is designed to provide a tight seal, which prevents water from leaking out of the hydrant when it’s not in use. This is especially important in dry-barrel hydrants, where the body of the hydrant is designed to remain empty until it is opened, preventing water from freezing in cold climates.

The operation of a gate valve is straightforward; it has a wedge or gate that moves vertically to stop or allow water flow. This mechanism offers full flow without restriction when the valve is open, making it an efficient choice for hydrants that need to deliver a large volume of water quickly.

In contrast, other types of valves such as ball valves and butterfly valves have different operating mechanisms and may not provide the same level of sealing and flow characteristics necessary for this specific application. Check valves, on the other hand, are designed to prevent backflow, which is not a function needed in a dry-barrel hydrant setup when it is properly designed and operated. Hence, the gate valve is the most suitable choice for dry-barrel hydrants.