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, vapors, 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.
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| Ball valve |
- Ball valve - for on/off control without pressure drop. Ideal for quick shut-off, since a 90° turn completely shuts-off, compared to multiple 360° turns for other manual valves.
Butterfly Valve - Butterfly valve - for on/off flow control in large diameter pipes.
Choke valve - Choke valve - raises or lowers a solid cylinder placed around or inside a second cylinder with holes or slots. Used for high pressure drops found in oil and gas wellheads, not to be confused with engine choke valve.
Diaphragm or Membrane valve - Diaphragm or Membrane valve - controls flow by the movement of a diaphragm. Used in pharmaceutical applications.
Gate Valve - Gate valve - mainly for on/off control, with low-pressure drop.
Glove valve - Globe valve - good for regulating flow. Uses a cylinder movement over a seat.
Knife valve - Knife valve -similar to a gate valve, but usually more compact. Often used for slurries or powders on/off control.
Needle Valve - Needle valve -for accurate flow control.
Pinch valve - Pinch valve - for slurry flow regulation and control.
Piston Valve - Piston valve -for regulating fluids that carry solids in suspension.
Plug Valve - Plug valve - slim valve for on/off control but with some pressure drop.
Solenoid Valve - Solenoid valve - an electrically actuated valve for hydraulic or pneumatic fluid control.
Spool Valve - Spool Valve - for hydraulic control, similar to the choke valve.
