Which term refers to valves, gauges, and devices used for regulation in engineering?

The correct term for valves, gauges, and devices that are used for regulation in engineering is instruments. This term encompasses a wide range of tools and devices designed to measure, control, or adjust the physical properties of systems, ensuring they operate efficiently and safely.

In the context of engineering, instruments play a vital role in monitoring variables such as pressure, temperature, flow rate, and level, allowing for precise control and regulation of processes. For instance, pressure gauges provide critical data on system pressures, while valves enable regulation of flow within piping systems.

Components is a broader term that includes any part of a system but does not specifically denote the regulatory function. Fittings, on the other hand, refer more to the mechanical elements used to connect pipes and do not include instruments. Connections are relevant for joining parts together but do not necessarily imply the function of regulation. Thus, instruments is the most accurate terminology in this context.