What action should you take when a fire hydrant is opened?

When a fire hydrant is opened, the correct action is to close it slowly. This approach is important for several reasons. First, closing the hydrant slowly helps to prevent water hammer, a phenomenon that can occur when water flow is suddenly stopped, causing a surge in pressure that can damage pipes and fixtures downstream. By easing the closure, the pressure can dissipate gradually, which minimizes the risk of such surges.

Additionally, closing a hydrant too quickly can lead to incomplete closure, which might result in leaks or the hydrant not sealing properly. This ensures that the hydrant is fully closed and helps maintain proper system pressure. It also ensures that any residual pressure in the system can be adequately managed.

Other actions, such as leaving the hydrant open or testing it weekly, do not directly address the operational best practice for closing a hydrant securely and safely once it has been opened for use.