Types of valves

1. 4-stroke cycle engine valves, Aspin valve, a cone-shaped metal part fitted to the cylinder head of an engine.
2. Ball cock, often used as a water level controller (cistern).
3. Ball valve, which is good for on/off control.
4. Bibcock, provides a connection to a flexible hosepipe
5. Blast valve, used to prevent rapid overpressures in a fallout shelter or a bunker.
6. Butterfly valve, particularly in large pipes.
7. Check valve or Non-return valve, allows the fluid to pass in one direction only.
8. Cock, colloquial term for a small valve or a stopcock.
9. Demand valve on a diving regulator.
10. Diaphragm valve, a sanitary valve predominantly used in the pharmaceutical industry
11. Double check valve.
12. A flow control valve maintains a constant flow rate through the valve.
13. Foot valve, a check valve on the foot of a suction line to prevent backflow.
14. Freeze valve, in which freezing and melting the fluid creates and removes a plug of frozen material acting as the valve.
15. Gate valve, mainly for on/off control.
16. Choke valve, Is a heavy duty valve which controls flow to a certain Flow Coefficient (CV) determined by how far the valve is opened, regularly used in the Oil industry.
17. Globe valve, which is good for regulating flow.
18. A heart valve regulates blood flow through the heart in many organisms.
19. Hydraulic valve (diaphragm valve).
20. A leaf valve is a one-way valve consisting of a diagonal obstruction with an opening covered by a hinged flap.
21. Needle valve for gently releasing high pressures.
22. Pilot valves regulate flow or pressure to other valves.
23. Piston valves
24. Plug valve, for on/off control.
25. A poppet valve is commonly used in piston engines to regulate the fuel mixture intake and exhaust. The sleeve valve is another valve type used for this purpose.
26. A pressure reducing valve (PRV), also called pressure regulator, reduces pressure to a preset level downstream of the valve.
27. A pressure sustaining valve, also called back-pressure regulator, maintains pressure at a preset level upstream of the valve.
28. Presta and Schrader valves are used to hold the air in bicycle tires.
29. A 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.
30. A regulator is used in SCUBA diving equipment and in gas cooking equipment to reduce the high pressure gas supply to a lower working pressure
31. Rotary valves and piston valves are parts of brass instruments used to change their pitch.
32. A saddle valve, where allowed, is used to tap a pipe for a low-flow need.
33. A safety valve or relief valve operates automatically at a set differential pressure to correct a potentially dangerous situation, typically over-pressure.
34. Schrader valves are used to hold the air inside automobile tires.
35. Solenoid valve, an electrically controlled hydraulic or pneumatic valve.
36. Stopcocks restrict or isolate the flow through a pipe of a liquid or gas.
37. Tap (British English), faucet (American English) is the common name for a valve used in homes to regulate water flow.
38. Thermostatic Mixing Valve
39. A three-way valve routes fluid from one direction to another.
40. Some trap primers either include other types of valves, or are valves themselves
41. Vacuum breaker valves prevent the back-siphonage of contaminated water into pressurized drinkable water supplies.