A Smart Relief Valve

The use in products pipelines of relief valves is discussed with the increasing demands on relief systems showing a need for a "smart" relief valve. A brief explanaton is given of hydraulic transient pressure waves and the computer programs that are now being used to model pipelines. The overall design of the relief system is discussed, including fail-safe protection. The need for fast action by the relief valve is emphasized. The concept of limiting relief action and step control of relief action is explained. The inputs to the microprocessor are reviewed, and the system of hardware to implement the logic (or programming) of the microprocessor which controls a relief valve is discussed.