Spotlight: Valves and actuators

摘要

Valves control fluid flow. A valve consists of a fluid-retaining assembly, one or more ports between end openings, and a moveable closure member that opens, restricts, or closes the ports. Valves can interrupt flow, regulated the flow rate, and divert flow to another branch of a system. Actuators-pneumatic, hydraulic, or electrically powered-supply force and motion to position a valve's closure member at or between the open or closed position.