The hydraulic component that directs fluid from normal or emergency sources to an actuating cylinder is called a what?

In hydraulic systems, the component that is responsible for directing fluid flow from either normal or emergency sources to an actuating cylinder is known as a shuttle valve. This device is specifically designed to select one of multiple fluid sources and direct the flow to a single output, such as a hydraulic cylinder. The shuttle valve acts as a decision point, allowing the system to switch from a primary supply source to a secondary source seamlessly.

A pressure relief valve serves a different purpose; it is used to prevent excessive pressure in the system by diverting fluid when a preset pressure level is exceeded. A pump is essential for moving fluid throughout the system, but it does not direct flow from multiple sources. Similarly, a flow restrictor is utilized to limit the flow rate within a circuit rather than directing fluid from multiple sources to an actuating cylinder. Therefore, the shuttle valve is the correct answer as it explicitly handles the task of directing fluid accordingly in response to system demands.