Which device temporarily stops the flow of water in a hose line?

The device that temporarily stops the flow of water in a hose line is known as a hose clamp. When applied to a charged hose line, the hose clamp pinches the hose, effectively stopping the flow of water without needing to disconnect the hose or shut down the water supply. This is particularly useful during operations where there may be a need to perform maintenance, make repairs, or transition to different tactics while still managing the water supply.

In firefighting scenarios, a hose clamp allows firefighters to control water flow safely and efficiently. The use of a hose clamp is crucial for maintaining safety and operational effectiveness in the field, as it permits multiple firefighters to work together without the risk posed by uncontrolled water flow.

The other devices mentioned in the choices have different functions: a hose jacket is used to protect a damaged hose, a hose roller facilitates the easy deployment and retrieval of hose lines, and a ball valve serves as a flow control device but doesn’t temporarily stop water flow in the same way a hose clamp does. The hose clamp is specifically designed for the task of stopping or controlling the water within a charged hose line, distinguishing it from the other devices.