Types of valves

A valve is a device that regulates, directs or controls the flow of a fluid  by opening, closing, or partially obstructing various passageways.

 Valves are technically fittings, but are usually discussed as a separate category. In an open valve, fluid flows in a direction from higher pressure to lower pressure. 

Valves are quite diverse and may be classified into a number of basic types. Valves may also be classified by how they are actuated:

• Hydraulic
• Pneumatic
• Manual
• Solenoid valve
• Motor