What type of valve is open when the handle is in line with the hose?

A ball valve is designed to allow or restrict flow through a pipeline with a smooth spherical ball that has a hole through its center. When the handle of a ball valve is turned so that it is in line with the hose, this indicates that the valve is in the open position, enabling fluid to flow freely through the valve and into the connected hose.

This design is advantageous for quick and reliable operation; it typically offers a full open or closed status with just a quarter turn of the handle, providing excellent control and making it very easy to determine if the valve is open or closed based on the handle's alignment.

In contrast, gate valves operate with a sliding gate mechanism and do not have a clear position indication based solely on the handle's alignment. Butterfly valves use a disc to control flow, which requires more detailed assessment for their open or closed status, and check valves are designed to allow flow in one direction and do not have a manual open/close function. Thus, the ball valve is the correct answer, as its design ensures that flow is enabled when the handle aligns with the pipe.