Valves are mechanical devices that control the flow and pressure within a system or process. They are essential components of a piping system that conveys liquids, gases, vapors, slurries, etc.. ... Some valves are self-operated while others manually or with an actuator or pneumatic or hydraulic is operated.

1. Under the shadow
of Industrial
Training
Program by Batch
2017, Chemical
Department.

2. Valve:
Any Device for closing
or modifying the
passage through a pipe,
outlet, inlet or likely to
stop, allow or control
the flow of a media.

3. VALVES
FUNCTION
➢ Starting and stopping flow
(On-Off Service),
➢Regulating flow volume
known as throttling,
➢Preventing reverse flow of
fluids (backflow),
➢Changing direction,
➢Control the fluid pressure,
➢Relieving component or
piping over pressure.

4. TYPES OF
VALVES acc. to
usage

5. Classification
of Valves Based on mechanical motion:
•Linear Motion Valves.
The valves in which the closure member, in a straight line to allow, stop, or
throttle the flow.
•Rotary Motion Valves.
When the valve-closure member travels along an angular or circular path.
•Quarter Turn Valves.
Some rotary motion valves require approximately a quarter turn, 0
through 90.

7. Globe Valves
A globe valve is a
linear motion valve
used to stop, start, and
regulate fluid flow.
The three primary
body designs for globe
valves are Z-body, Y-
body, and Angle.

8. Globe Valves
Advantages
o Recommended for throttling applications.
o Good for frequent operation.
o Easy to repair.
Disadvantages
o Flow path causes a significant
pressure drop.
o Globe valves are more costly
than alternative valves.

9. Gate Valves
Flow is controlled by
raising or lowering the
valving element.
➢It is not use to regulate
flow because the
valving element can be
damaged when in the
partially open position.
➢75% of all valves in
process industries are
gate valves.

10. Gate Valves
Advantages
- Gate valves opens or closes
slowly, which prevents fluid
hammer and subsequent
damage to the piping system.
-Good choice for on-off
service.
-Full flow, low pressure drop.
Disadvantages
- It is not suitable for
throttling applications.
- It is prone to vibration in the
partially open state.
- Repairing are generally more
difficult.

11. Knifegate Valves
❑Often just called gate
valves, these are used
as isolation valves.
❑The principle is
simply a knife or gate
which is dropped in
front of the flow.

12. Ball Valves
A ball valve is a
rotational motion
valve that uses a ball-
shaped disk to stop
or start fluid flow.

13. Ball Valves Advantages
- Maintains and regulates high volume, high pressure, and high
temp flow.
- Low purchase and maintenance costs.
- No lubrication requirements.
- Give tight sealing with low torque.
- Time of valve operation is minimized.
- Can be used for throttling service.
- Can handle fluids with suspended solids.
Disadvantages
- Have relatively poor throttling
characteristics.
- Difficult to clean.

14. Butterfly
Valves
Butterfly valves are
rotary motion valve
that is used to stop,
regulate, and start
fluid flow.

15. Butterfly
Valves
Advantages
◦ Compact, lightweight design.
◦ The maintenance costs are usually low.
◦ Pressure drop across a butterfly valve is small.
◦ Used with chemical or corrosive media.
Disadvantages
◦ Difficult to clean
◦ Throttling limited to low
differential pressure.
◦ Potential for cavitations and choke.
◦ Unguided disc movement is
affected by flow turbulence.

16. Diaphragm
Valves
A diaphragm valve is a
linear motion valve
that is used to start,
regulate, and stop fluid
flow.
The name is derived
from its flexible disk.

17. Diaphragm
Valves Advantages
- Valve components can be isolated from the process fluid.
- Valve construction prevents leakage of the fluid without
the use of a gland seal (packing).
Disadvantages
- The diaphragm becomes worn more easily and regular
maintenance is necessary.
- These types of valves are generally not suited for very high
temperature fluids and are mainly used on liquid systems.

18. Pinch Valve
It is a linear motion
valve that is used to
start, regulate, and
stop fluid flow.
It uses a rubber tube
(pinch tube) to
control the fluid.

19. Pinch Valve
Advantages
 Use for handling of slurries, liquids with large amounts of
suspended solids.
 The flow passage is straight without any crevice.
 There are no internal moving parts in contact with the fluid.
 Low maintenance due to wear or pressure.
Disadvantages
 Cannot be used in high temperature/ pressure applications.
 Cannot be used with gas media.

20. Plug valve
A plug valve is a rotational motion valve.
Applications
● Gas and liquid fuel ,Water.
● Extreme temperature flow
● Boiler feed water.
● Low Pressure Steam.
● Corrosive Liquids and Gases

21. Check Valves
 Check valves are designed to prevent
the reversal of flow in a piping system.
 The pressure of the fluid passing
through the system opens the valve,
while any reversal of flow (back
pressure) will close the valve.

22. RELIEF VALVES
❖When pressure of fluid exceeds
a predetermined limit, the
valve operates automatically
and open.
❖These are also known as the
automatic cut-off valves or
safety valves.
❖The relief valves are located at
every point along the water
pipe where pressure is likely to
be maximum.

23. FLAP VALVES
A protective device
installed in a drainage
system to guard
against the effect of
back flooding caused
by surcharge.

24. FOOT VALVE
Foot valves are a type of
check valve. Unlike
other valves, a foot
valve is created with a
larger flow area.