List of valves

The inside of an extremely large butterfly valve

Duplex ball valve

Three check valves in corrosion-resistant Hastelloy

Stainless steel gate valve

Valves can be categorized into the following types, based on their operating mechanism.

• 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, for on/off flow control in large diameter pipes.
• 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, controls flow by movement of a diaphragm. Used in pharmaceutical applications.
• Gate valve, mainly for on/off control, with low pressure drop.
• Globe valve, good for regulating flow. Uses a cylinder movement over a seat.
• Knife valve, similar to a gate valve, but usually more compact. Often used for slurries or powders on/off control.
• Needle valve for accurate flow control.
• Pinch valve, for slurry flow regulation and control.
• Piston valve, for regulating fluids that carry solids in suspension.
• Plug valve, slim valve for on/off control but with some pressure drop.
• Solenoid valve, an electrically actuated valve for hydraulic or pneumatic fluid control
• Spool Valve, for hydraulic control, similar to the choke valve

Valves can be categorized also based on their function

• Check valve or non-return valve, allows the fluid to pass in one direction only.
• Flow control valve, to maintain and control a variable flow rate through the valve
• Poppet valve, commonly used in piston engines to regulate the fuel mixture intake and exhaust
• Pressure Reducing Valve, to regulate the pressure of the fluid.
• Thermal expansion valve, used in refrigeration and air conditioning systems.
• Safety valve or relief valve: operates automatically at a set pressure to correct a potentially dangerous situation, typically over-pressure
• Sampling valve

These are more specific types of valves, used only in particular fields or applications. Often they are subcategories of the classification by operating principle and by function.

• Aspin valve: a cone-shaped metal part fitted to the cylinder head of an engine
• Ball cock: often used as a water level controller (cistern)
• Bibcock: provides a connection to a flexible hosepipe
• Blast valve: prevents rapid overpressuring in a fallout shelter or a bunker
• Boston valve: three-part two-port check valve used on inflatable boats, air mattresses, airbeds etc.; available in two sizes, normal and small
• Cock: colloquial term for a small valve or a stopcock
• Ceramic Disc valve, used mainly in high duty cycle applications or on abrasive fluids. Ceramic disc can also provide Class IV seat leakage
• Choke valve, Butterfly valve used to limit air intake in internal combustion engine. Not to be confused with choke valves used in industrial flow control.
• Clapper valve: a type of check valve used in the Siamese fire appliance to allow only 1 hose to be connected instead of two (the clapper valve blocks the other side from leaking out).
• Demand valve: on a diving regulator
• Double beat valve
• Double check valve
• Duckbill valve
• Fill and drain valve: a valve used in space and missile industry which achieves extremely tight leakage, while providing redundant inhibits against external leakage[1]
• Flapper valve
• Flow divider valve: a valve providing a plurality of output flows from a single fluid source[2]
• Flutter (Heimlich) valve: a specific one-way valve used on the end of chest drain tubes to treat a pneumothorax
• Foot valve: a check valve on the foot of a suction line to prevent backflow
• Four-way valve: was used to control the flow of steam to the cylinder of early double-acting steam engines
• Freeze seal/Freeze plug: in which freezing and melting the fluid creates and removes a plug of frozen material acting as the valve
• Gas pressure regulator regulates the flow and pressure of a gas
• Heart valve: regulates blood flow through the heart in many organisms
• Hydrodynamic vortex valve: a passive flow control valve that uses hydrodynamic forces to regulate flow
• Larner–Johnson Valve: needle control valve often in large sizes used in water supply systems
• Leaf valve: one-way valve consisting of a diagonal obstruction with an opening covered by a hinged flap
• Line blind valve: a thin sheet oriented perpendicular to the pipe. The sheet has a solid end and a flow-through end; sliding it from one position to the other opens or stops the flow. Also called sliding blind valve.
• Outflow valve: regulates flow and pressure, part of cabin pressurization.
• Pilot valve: regulates flow or pressure to other valves
• Pinch valve, "beach ball valve": simple, single-part two-port check valve made from soft plastic and molded on to inflatable units such as beach balls, air mattresses, water wings; can be inflated by pump or by mouth.
• Plunger valve: To regulate flow while lowering the pressure
• Poppet valve and sleeve valve: commonly used in piston engines to regulate the fuel mixture intake and exhaust
• Pressure regulator or pressure reducing valve (PRV): reduces pressure to a preset level downstream of the valve
• Pressure sustaining valve, or back-pressure regulator: maintains pressure at a preset level upstream of the valve
• Presta, Schrader or Dunlop valves are used to hold the air in bicycle tires
• Reed valve: consists of two or more flexible materials pressed together along much of their length, but with the influx area open to allow one-way flow, much like a heart valve
• Regulator: used in SCUBA diving equipment and in gas cooking equipment to reduce the high pressure gas supply to a lower working pressure
• Rocker valve
• Rotolock valve
• Rotary valves and piston valves: parts of brass instruments used to change their pitch
• Rupture disc: a one time use replaceable valve for rapid pressure relief, used to protect piping systems from excessive pressure or vacuum; more reliable than a safety valve
• Saddle valve: where allowed, is used to tap a pipe for a low-flow need
• Schrader valve: used to hold the air inside automobile tires
• Slide valve: used in early steam engines to control admission and emission of steam from the piston.
• Slide gate valve: Slide Gate Valves. Ideal for handling dry bulk material in gravity flow, dilute phase or dense phase pneumatic conveying applications. Similar to a sliding line blind valve, but the latter is for higher-pressure applications.
• Stopcock: restricts or isolates flow through a pipe
• Swirl valve: A specially designed Joule-Thompson pressure reduction/expansion valve imparting a centrifugal force upon the discharge stream for improving gas–liquid phase separation
• Tap (British English), faucet (American English): the common name for a valve used in homes to regulate water flow
• Tesla valve: A form of check valve with no moving parts, invented by Nikola Tesla for use with fluids.
• Thermostatic mixing valve
• Thermostatic radiator valve
• Trap primer: sometimes include other types of valves, or are valves themselves
• Vacuum breaker valve: prevents the back-siphonage of contaminated water into pressurized drinkable water supplies