- Definition and Basic Principles
- Valve regulates fluid flow by opening, closing or partially obstructing passages
- Fluid flows from higher to lower pressure in open valves
- Word derived from Latin "valva" meaning door part
- Main Components
- Body contains internal parts and bonnet provides cover
- Ports allow fluid passage through valve
- Stem transmits motion from handle to disc
- Seat contacts disc for leak-tight seal
- Types and Applications
- Valves range from 0.1mm to 60cm diameter
- Used in industrial processes, household appliances, and natural systems
- Can be manual or automatic controlled by actuators
- Common types include check valves, butterfly valves, and ball valves
- Control and Operation
- Manual control uses handles or handwheels
- Automatic control requires actuators like motors or solenoids
- Valves rated for maximum temperature and pressure
- Regular maintenance includes checking for leaks
- Material and Construction
- Bodies made of metals like steel, brass, or plastic
- Seats can be hard (integral) or soft (fitted)
- Springs used for normal position adjustment
- Gaskets prevent fluid leakage