What are Valves?
Valves are mechanical devices that control the flow and pressure within a system or process. They are essential components of a piping system that conveys liquids, gases, vapours, slurries etc..
Different types of valves are available: gate, globe, plug, ball, butterfly, check, diaphragm, pinch, pressure relief, control valves etc. Each of these types has a number of models, each with different features and functional capabilities. Some valves are self-operated while others manually or with an actuator or pneumatic or hydraulic is operated.
Functions from valves are
1- Stopping and starting flow
2- Reduce or increase a flow
3- Controlling the direction of flow
4- Regulating a flow or process pressure
5- Relieve a pipe system of a certain pressure
Different Types of Valve with P&ID symbols
