This work features insights on valve sizing, smart (digital) valve positioners, field-based architecture, network system technology, and control loop performance evaluation. Hans Baumann, a holder of more than 150 patents, and author of over a hundred publications in control valve technology, shares his expertise on designing control loops and selecting final control elements. This easy-to-read text provides shortcuts through complex sizing and noise calculation formulas including for liquids and cavitation, and gives practical advice on how to apply control valves for safety, reduced energy costs, loop stability, and easy maintenance.