A hydrant flange is a crucial component in a fire hydrant, particularly in certain types like dry-barrel hydrants. Based on the provided reference, it can refer specifically to a "break-away" flange.
Understanding the Break-Away Hydrant Flange
The reference describes a "break-away" flange as part of a dry-barrel hydrant structure. Located typically at ground level, this flange serves a vital safety and maintenance purpose.
Purpose and Function
The primary function of the break-away flange, as highlighted in the reference, is to act as a sacrificial point in the hydrant's structure. If the hydrant is struck by a vehicle or other heavy object:
- It allows the hydrant to break off at ground level.
- This mechanism usually prevents damaging the valve which is located below ground level.
This design is essential because damaging the main valve can lead to significant water loss, costly repairs, and disruption to water supply. By breaking at the flange, the above-ground portion is sacrificed, while the critical, buried valve remains intact and operational or easily repairable without major excavation.
Location in a Dry-Barrel Hydrant
Looking at a dry-barrel hydrant from top to bottom, as mentioned in the reference:
- Operating nut (top)
- Bonnet assembly
- Dry-barrel with outlets (e.g., 4.5-inch and two 2.5-inch outlets)
- The "break-away" flange (typically near ground level)
- Barrel section extending underground
- Main valve (bottom, underground)
| Component | Typical Location | Primary Function |
|---|---|---|
| Operating Nut | Top | Used to open/close the valve |
| Break-Away Flange | Near Ground Level | Allows the hydrant to break upon impact |
| Main Valve | Underground | Controls water flow to the hydrant outlets |
This design ensures that impacts above ground minimize damage to the underground infrastructure.
Other Types of Flanges on Hydrants
While the reference focuses on the break-away flange, hydrants utilize other flanges for connections:
- Base Flange: Connects the bottom barrel section to the main valve or elbow underground.
- Outlet Flanges: Connect the hydrant outlets (nozzles) to the barrel. These are typically bolted connections.
However, when discussing a "hydrant flange" in the context of safety and impact resistance, the "break-away" flange near ground level is often the key component being referred to, especially in dry-barrel designs common in areas subject to freezing temperatures.
In summary, a hydrant flange can refer to various connection points, but the break-away flange near ground level in dry-barrel hydrants is a critical safety feature designed to protect the underground valve from traffic impacts.
