Valve Theory
Several types of valves are in use at any one time in a pressurized system. These valves have different behaviors due to their different purposes, but all valves are used for controlling flow. They can be opened, closed, or throttled to achieve the desired result. In terms of hydraulic transient analysis and design, valves can be classified as flow control or surge control valves. Flow control valve types are discussed in Flow-Control Valve Fundamentals: