When connecting to a hydrant, what device should be placed on the discharge opposite the direction of the line?

The correct answer involves using a gate valve on the discharge opposite the direction of the line when connecting to a hydrant. A gate valve is specifically designed to provide a straightforward on/off control of the water flow. When placed in the correct orientation, it ensures that the water can be completely shut off when necessary, allowing for safe maintenance or adjustments without risking water loss or pressure issues.

The placement of the gate valve is crucial for controlling water flow and facilitating safe operations in various situations, such as during firefighting or when connecting hoses. This setup helps prevent backflow and allows for effective management of water distribution from the hydrant.

Other devices, while they may have their own specific uses, do not function in the same way as a gate valve for this particular application. For instance, a flow meter is generally used for measuring the volume of water flowing through a system, while a reducing valve is designed to lower the pressure of the water, and a ball valve is typically used for quick shut-off but may not provide the same sealing effectiveness in certain contexts as a gate valve. Thus, for this scenario focused on efficient and secure control of water flow from the hydrant, the gate valve is the most suitable choice.