The use of valves in piping is to stop or control fluid flow. Valves come in many different designs and end types but generally they will comply with the P&ID and the piping specification. Generally valves are designed to ASME B16.34 standard, other standards will apply to valve types, applications etc.
Valve function more than any other single criteria limits the choice when selecting a valve, therefore we shall categorize valve function in the following groupings:
- ON-OFF SERVICE
Gate Valves
Plug Valves
Ball Valves
- THROTTLING SERVICE
Globe Valves
Butterfly Valves
Diaphragm Valves
Pinch Valves - PREVENTION OF BACKFLOW
Check Valves
Categorizing valves as above does not necessarily mean that these listed are only used for that function, for example, a ball valve may be used for mild throttling service.
