Types of Valves | Classification of Valves

 Types of Valves

Various types of Valves have been developed to cater to the diversified requirements of fluid control in various applications. These types of valves match the systems, fluids, and environments to accomplish their intended function.

Each type of valve has been designed to meet specific needs. Some valves are capable of throttling flow, other valve types can only stop flow, others work well in corrosive systems, and others valves handle high-pressure fluids. Each valve type has certain inherent advantages and  disadvantages. Understanding these differences and how they affect the valve’s application or operation is necessary for the successful operation of a facility.

Although all valves have the same basic components and function to control flow in some fashion, the method of controlling the flow can vary dramatically.

Each method controlling flow has characteristics that make it the best choice for a given application of function. One valve may be best fit for one application but may not be fit for other at the same time.

Classification of Valves

Fluid control valves are classified in many ways. Following is the classification of valves.

Multi Turn and Quarter Turn Valves

Multi turn valves need many turns of actuator to bring closure member (disc) from fully open position to fully closed position. Examples of multi turn valves are gate valves, globe valves, needle valves, and diaphragm and pinch valves.

While quarter turn valves need only quarter ,0 to 900 degree, motion of closure member (disc) to bring it from full open position to full closed position.  Examples of quarter turn valves are butterfly valves, ball vales and plug valves etc. Quarter turn vales are quick opening valves.

Self actuated Valves

Self actuated valves don’t need actuator to operate them. These valves operate based on some property of fluid line like pressure or flow. Self actuated valves don’t need operator’s interference to control the fluid. Examples of self actuated valves are check valves and pressure relief valves or safety valves.

Linear Motion and Rotary Motion Valves

In linear motion valves, disc moves in linear or straight path to open, close or throttle the flow in valve. While in Rotary motion valves, disc rotates to open, close or throttle the flow. Examples of linear motion valves are gate valves, needle valves, globe valves, diaphragm valves and pinch valves. Examples of Rotary motion valves are ball valves, butterfly valves etc.

General Types of valves

In general following are the types of valves.

• Gate valve
• Globe Valve
• Pinch Valve
• Needle valve
• Diaphragm valve
• Ball valve
• Butterfly Valve
• Check valve
• Pressure relief Valve (safety or relief valve)