A valve is a device that controls flow, a definition that barely begins to describe the current valve landscape. Valves today can direct and regulate flow, rate, volume, and pressure of liquids, gases, and other materials. They come in many shapes and sizes and are fundamental to nearly every venture into manufacturing and production. The Valve Manufacturers Association of America puts it best when it claims, “The valve is one of the most basic and indispensable components of our modern technology society.”

Below is an illustrated guide to common types of valves used in industrial settings today.

 

Relief valve, or safety valve

Self-actuated valve

Relief Valve
Function
  • Protects from overpressure
Usage notes
  • Opens and closes to limit the amount of pressure
  • Prevents damage to a system

Pilot valve

Pilot Valve
Function
  • Controls the flow to a separate valve
Usage notes
  • Reduces the force necessary to control a high-pressure or high-flow feed
  • Excellent for emergency and safety controls

Gate valve

Multi-turn or linear motion valve

Gate Valve
Function
  • On/off control
  • Non-throttling
Usage notes
  • Excellent for heavy and solid liquids
  • Isolates pipe systems

Globe valve

Multi-turn or linear motion valve

Globe Valve
Function
  • On/off control
  • Throttling
Usage notes
  • Excellent for regulating flow of thick or corrosive fluids
  • Ports may be straight or at an angle

Check valve, or non-return valve

Self-actuated valve

Check Valve
Function
  • Allows flow in only one direction
Usage notes
  • Prevents backflow
  • Types include ball check valves, piston check valves, swing check valves, and tilting disc check valves

Ball valve

Quarter-turn or rotary valve

Ball Valve
Function
  • On/off control
  • Some throttling
Usage notes
  • Excellent for quick shut-off
  • Versatile, supporting high temperatures and pressures

Control valve

 

Control Valve
Function
  • Accurate control of flow, temperature, pressure, and liquid level
Usage notes
  • Varies flow rate based on external sensors
  • Many types of valves can be used as control valves

Plug valve

Quarter-turn or rotary valve

Textstream Plug Valve
Function
  • On/off control
  • Some throttling
Usage notes
  • May have some pressure drop

Butterfly valve

Quarter-turn or rotary valve

Butterfly Valve
Function
  • On/off control
  • Throttling
Usage notes
  • Limited control capacity
  • Some pressure drop, regardless of valve position

Low pressure/vacuum vent

Low Pressure Vacuum Vent Valve
Function
  • Protects against an internal vacuum
Usage notes
  • Excellent for protecting equipment, such as liquid storage tanks, from structural damage

Flame arrester

 

Flame Arrester
Function
  • Stops a flame to prevent it from developing into a fire
Usage notes
  • Protection for lines and pipe systems
  • Frequently used in fuel storage tanks and gas pipelines

Picture of plug valve by Heather Smith (The Alloy Valve Stockist‘s photo gallery) [CC-BY-3.0], via Wikimedia Commons