2. What is a Valve?
• A valve is a component of the piping
network.
• It is a mechanical device, controlling or
modifying the flow and pressure within a
pipeline that convey liquids and gases.
• A valve stops, allows, control and modifies
flow of a fluid media.
• A valve blocks a pipe either partially or
totally, thereby regulating the amount of
liquid or gas that flows through it.
3. How is a valve operated?
Valves can be operated:
• Manually
• Automatically
• Pneumatically
• Hydraulically
• With the help of an actuator
4. Functions of a Valve
The valve carries out the following functions –
• To enable and stop the flow of media (liquid or gas)
• To increase or decrease the flow of media
• To regulate the direction of media flow
• To regulate the pressure of media flow
• To relieve the pipeline of pressure
5. What is a Valve made of?
• A valve is made of plastic,
rubber and metal.
• The outer part of the valve, the
seat, is made of a solid metal
casting on the outside with a soft
inner rubber or plastic seal.
6. • This metal-rubber-plastic
combination helps the valve
to have a tight end.
• The inside part of the valve,
called the body, fits into the
seat when the valve is
closed. It is the body that
opens and closes.
7. Classification of Valves
A valve is classified depending on
its mechanical motion. Valves can
be classified into three categories:
• Linear motion valve – In these
valves, the closure member
moves in a straight path, stopping
or letting the flow.
8. • Rotary motion valve – In these
valves, the closure member moves
in a circular path, stopping or
letting the flow.
• Quarter turn valve - – In these
valves, the closure member moves
in an exactly quarter path, stopping
or letting the flow.
