What accessories are commonly used with control valves?

Common valve accessories: positioner (accurate positioning, diagnostics), I/P converter (signal conversion without positioner), limit switches (position indication), solenoid valves (on-off control, fail-safe action), boosters (faster response for large actuators), lock-up valves (fail-last position), handwheel (manual override), and position transmitter (remote indication). Selection depends on application: positioner for most control valves, solenoid for on-off valves, limit switches for safety systems, and boosters for fast response requirements. Specify accessories on valve datasheet with mounting and signal requirements.