The Difference Between Wet Barrel and Dry Barrel Hydrants Explained

There are two main types of fire hydrants: wet barrel and dry barrel. Each type has its own unique features and is suited to different climates and conditions. Here's a closer look at the differences between wet barrel and dry barrel hydrants.

image taken from Complete Fire and Pumps

Wet Barrel Hydrants

What Are They? Wet barrel hydrants are designed so that water is always present in the hydrant up to each outlet. These hydrants are commonly found in areas with mild or warm climates, where the risk of freezing is minimal.

Key Characteristics:

• Continuous Water Supply: Water is always available up to the hydrant outlets, which means firefighters can access water immediately by opening a valve.
• Individual Outlet Control: Each outlet on a wet barrel hydrant has its own valve, allowing for multiple hoses to be connected and operated independently.
• Easy Maintenance: Because the hydrant is always filled with water, there is no need for additional components to prevent freezing, simplifying maintenance.
• Not Suitable for Cold Climates: In freezing conditions, the water inside a wet barrel hydrant can freeze, potentially damaging the hydrant and making it unusable during an emergency.

Best Suited For:

• Regions with warm or moderate climates.
• Areas where freezing temperatures are rare or non-existent.

Dry Barrel Hydrants

What Are They? Dry barrel hydrants are specifically designed for colder climates. Unlike wet barrel hydrants, they do not hold water in the barrel when not in use. Instead, the water supply is controlled by a valve located below the frost line.

Key Characteristics:

• Freeze Protection: The main valve is situated below the frost line, ensuring that water does not remain in the hydrant barrel where it could freeze.
• Main Valve Operation: When the hydrant is opened, the valve below ground allows water to fill the barrel and flow out through the outlets.
• Self-Draining: After use, the hydrant drains any remaining water back below the frost line, ensuring that the barrel stays dry and protected from freezing.
• More Complex Maintenance: These hydrants require regular inspections and maintenance to ensure the main valve functions correctly and to prevent leaks.

Best Suited For:

• Regions with cold climates and frequent freezing temperatures.
• Areas where reliable operation in winter conditions is critical.

Key Differences Summary

Selecting the appropriate type of fire hydrant is crucial for ensuring effective fire protection and minimizing maintenance challenges. Wet barrel hydrants are ideal for warm climates, offering easy access and simple operation. Dry barrel hydrants, on the other hand, are essential for colder regions, designed to prevent freezing and ensure reliable performance in harsh winter conditions. Understanding these differences helps municipalities and fire departments maintain a robust and responsive fire protection infrastructure.