2. Goals
Understanding the function of valves
Knowing valves major components
Knowing valves classification
To know
- Application of each valve type
- Material
- Installation and, Maintenance tips
2
3. Definition
Valves are mechanical devices that
control the fluids through pipes by
Changing the
flow rate
Starting and
stopping.
Allowing flow
in one
direction only.
Adjusting
fluid
pressure.
Re-directing
flow
Preventing
accidents by
relieving
overpressure
3
4. Valves Selection
4
Factors affecting the suitability and
application of valves
Fluid
Properties
Valve Size
Valve
Service
Fluid
Friction
Loss
Pressure
and
temperature
9. 9
Valves
Classification
- ON-OFF (Block Valves)
Gate Valve Relief Valve
Plug Valve Tank-Bottom Valve
Ball Valve
Used To
Start or stop the flow of the medium through the process
Hand-operated and can be automated with the addition of an actuator
Guard against over pressurization
Valve
Function
11. 11
Valves
Classification
Used To
Regulate the flow, temperature, or pressure of the service
Be act as on-off valves also
- Throttling Valve
Hand-Operated Valves
Automatic Valves
Valve
Function
14. 14
Valves
Classification
- General Service
Valve
Application
Used For
Lower-pressure ratings (16 to 100 bar.)
Moderate-temperature ratings -50 to 650°F (-46 to 343°c)
Non corrosive fluids, and common pressure drops that do not result in
cavitation or flashing.
19. 19
Valves
Classification
Valve Motion
- Linear-Motion Valves (Linear Valves)
Gate Valve Diaphragm Valve
Globe Valve Pinch Valve
3 Way and, angle Valve
Have A sliding stem design that pushes A closure element into an open or closed position.
20. 20
Valves
Classification
Valve Motion
- Rotary-Motion Valves (Rotary Valves)
Ball Valve
Butterfly Valve
Plug Valve
Use a closure element that rotates through a quarter-turn or 45° range to open or block the flow.
26. 26
Valves
Classification
Definition Recommended Application Advantages Disadvantages Variations Materials Special
installation
and,
maintenance
instructions
Ordering
specifications
Multi-turn valve
in which the port
is closed by A
flat-faced,
vertical
Disk that slides
at right angles
Over the seat.
1- for fully open
or fully
Closed, non
throttling service.
2- for infrequent
operation.
3- for minimum
resistance to flow.
4- for min.
Amounts of fluid
trapped in line
1- general
service
2- oil, gas, air,
slurries, steam
3- non
condensing
gases and
4- liquids ,
corrosive
liquids
1- high capacity
2- tight shutoff
3- low cost
4- simple design
and operation.
5- little
resistance to
flow.
1- poor flow
control
2- high
operating force.
3- cavities at low
pressure drop.
4- must be kept
in full open or
full closed
position.
5- throttling
position will
erode seat
and disk
1- solid wedge
2- flexible wedge
3- split wedge
4- double disk
Body
Bronze,
cast
iron ,
iron
Forged
steel,
cast
steel,
Stainles
s steel,
PVC
plastic
1- lubricate or
regular
schedule.
2- correct
packing leaks
immediately.
3- always cool
system when
closing
down a
“hot” line and
checking
closed
valves.
4- never force
valves closed
with
wrench or
pry.
5- open valves
slowly to
prevent
hydraulic
shock in line.
6- close valves
slowly to help
flush
trapped
sediment and
dirt.
1- type of end
connection.
2- type of
wedge.
3- type of seat.
4- type of stem
assembly.
5- type of
bonnet
assembly.
6- type of stem
packing
7- operating
pressure.
8- operating
temperature.
Trim Various
Gate
Valve
27. 27
Valves
Classification
Definition Recommended Application Advantages Disadvantages Variations Materials Special
installation
and,
maintenance
instructions
Ordering
specifications
Quarter-turn
valve that
controls flow
By means of
cylindrical or
tapered
Plug with A hole
through the
center,
Which can be
positioned from
open
To close by A
90° turn.
1- for fully open
or fully closed
2- for frequent
operation.
3- for minimum
resistance to flow.
4- for min.
Amounts of fluid
trapped in line.
5- for low press.
Drop across
valve
1- general
service
2- slurries,
3- vapors and
gases
4- liquids ,
corrosive
liquids
1- high capacity
2- tight shutoff
3- low cost
4- quick
operation.
1- high torque
for actuation.
2- cavitation at
low pressure
drop.
3- seat wear.
1- lubricated
2- non lubricated
3- multi port
Ductile iron , iron
Carbon steel,
nickel,
Stainless steel,
plastic
Ductile iron ,
iron
Carbon steel,
nickel,
Stainless
steel, plastic
1- body material
2- plug material
3- operating
pressure.
4- operating
temperature.
5- port
arrangement, if
multiport .
6- lubricant, if
lubricated valve
Plug
Valve
28. 28
Valves
Classification
Definition Recommended Application Advantages Disadvantages Variations Materials Special
installation
and,
maintenance
instructions
Ordering
specifications
Multi-turn valve
in which closure
is activated by
means of A disk
or plug that seals
or stops the fluid
on A
Seat generally
parallel to the
line flow.
1- for throttling or
flow regulation.
2- for frequent
operation.
3- for positive
shutoff of gases
or air
4- where some
resistance to flow
is acceptable.
1- general
service
2- slurries,
3- vapors and
gases
4- liquids ,
corrosive liquids
1- efficient
throttling with
min. wire drawing
or disk or seat
erosion.
2- short disk
travel and fewer
turns to operate,
saving time and
wear on stem
and bonnet.
3- accurate flow
control.
1- high pressure
drop.
2- relatively high
cost.
.
1- standard
2- Y pattern
3- angle
4- three - way
Body Bronze,
cast iron
, iron
Forged
steel,
cast
steel,
Stainless
steel,
plastics
1- install so
pressure is
under disk,
except in high
temperature
steam Service.
2- lubricate on
strict schedule.
3- flush foreign
matter off seat
by opening
valve slightly.
4- correct
packing leaks
immediately
by tightening
the packing
nuts.
1- type of end
connection.
2- type of disk.
3- type of seat.
4- type of stem
assembly.
5- type of
bonnet
assembly.
6- type of stem
packing
7- operating
pressure.
8- operating
temperature.
Trim Various
Globe Valve
29. 29
Valves
Classification
Definition Recommended Application Advantages Disadvantages Variations Materials Special
installation
and,
maintenance
instructions
Ordering
specifications
Quarter-turn
valve in which a
drilled
ball rotates
between resilient
seats,
allowing straight-
through flow in
the open position
and shutting off
flow when the
ball, is rotated
90°
and blocks the
flow passage.
1- for on-off , non
throttling service.
2- where quick
opening is
required.
3- for minimum
resistance to flow
is needed.
4- for moderate
temp.
requirements.
1- general
service
2- slurries,
3- high
temperatures.
1- high capacity
2- tight shutoff
3- low cost
4- compact
5- low leakage.
6- no lubrication
requirements.
7- low
maintenance.
8- bidirectional
shutoff
1- high torque
for actuation.
2- poor throttling
characteristics.
3- susceptible to
seal wear.
4- prone to
cavitation.
.
1- top entry,
split body or
end entry.
2- three-way,
3- full- ported.
4- reduced
port.
Body Bronze,
cast&
ductile iron,
brass,
aluminum,
titanium
stainless
steel, and
plastics
1- allow space
for operation
of long
Handle
1- body material
2- seat material
3- type of port in
ball.
4- operating
pressure.
5- operating
temperature.
6- full or
reduced port.
7- top enter or
side entry.
Trim TFE, filled
TFE, nylon
Ball
Valve
30. 30
Valves
Classification
Definition Recommended Application Advantages Disadvantages Variations Materials Special
installation
and,
maintenance
instructions
Ordering
specifications
Quarter-turn
valve that
controls flow
by means of
circular disk with
its port axis at
right angles to
the direction of
flow.
1- for fully open
or fully closed.
2- for frequent
operation.
3- for throttling
service.
4- for min.
amounts of fluid
trapped in line is
allowed.
5- for low press.
drop across
valve
1- general
service
2- slurries, liquids
with suspended
solids
3- liquids, gases.
1- light weight
2- low cost
3- compact
4- no pockets
5-highcapacity.
6- self- cleaning
7- straight –
through flow
8- low
maintenance.
9- minimum
number of
moving parts.
1- high torque
for actuation.
2- limited
pressure drop
capability.
3- prone to
cavitation.
.
1- wafer, lug
wafer.
2- flanged,
screwed,
3- fully- lined.
4- high-
performance.
Body iron ,
ductile iron,
bronze
carbon
steel ,
stainless
steel,
1- may be
operated by
lever, hand
wheel, or
chain
2- allow
sufficient
space for
operation
of handle if
lever operated.
3- valves
should remain
in closed
position
during all
handling and
installation
operations.
1- type of body
2- type of seat
3- body material
4- seat material
5- disk material.
6- operating
pressure.
7- operating
temperature.
8- type of
actuation.Trim all metals,
elastomer
coating
such as
TFE,
neoprene
Seat TFE, filled
TFE, nylon
Butterfly
Valve
31. 31
Valves
Classification
Definition Recommended Application Advantages Disadvantages Variations Materials Special
installation
and,
maintenance
instructions
Ordering
specifications
Multi-turn valve
that effects
closure
by means of a
flexible
diaphragm
attached to a
compressor .
when
compressor is
lowered by the
valve stem, the
diaphragm seals
and
cuts off flow
1- for fully open
or fully closed.
2- for throttling
service.
3- for service
with low
operating
pressure.
1- corrosive fluids,
2- sticky and/or
viscous materials
3- fibrous slurries,
sludge,
4- foods, and
pharmaceuticals.
1- low cost
2- no packing
glands.
3- no
possibility of
stem leakage.
4- immune to
problems of
clogging,
corroding, or
gumming of
media
1- diaphragm
subject to wear
2- high torque
under live- line
closure.
1- weir type
and
2- straight-
through type.
metallic, solid plastic,
lined- wide
variety of each.
1- lubricate on
regular
schedule.
2- do not use
bars,
wrenches, or
cheaters to
close
1- body material
2- diaphragm
material
3- end
connections.
4- type of stem
assembly.
5- type of
bonnet
assembly.
6- type of
operation.
7- operating
pressure.
8- operating
temperature.
Diaphragm
Valve
32. Definition Recommended Application Advantages Disadvantages Variations Materials Special
installation
and,
maintenance
instructions
Ordering
specifications
Multi-turn valve
that effects
closure
by means of one
or more flexible
elements, such
as diaphragms
or rubber tubes
,that can be
passed
together to cut
off flow.
1- for on-off
service.
2- for throttling
service.
3- for moderate
temperatures.
4- where
pressure drop
through valve is
low.
5- for services
requiring low
maintenance
1- slurries, mining
slurries,
2- liquids with
large amounts of
suspended solids,
3- systems that
covey solids,
4- foods, and
pharmaceuticals.
1- low cost
2- simple
design.
3- low
maintenance.
4- no internal
obstruction or
Pockets to
cause clogging.
5- non corrosive
and abrasion-
resistant
1- limited
vacuum
application
2- difficult to size.
1- exposed
sleeve or body,
2- encased
metallic sleeve
or body
Rubber, white rubber
Hypalon, neoprene,
whit neoprene
Bunna-n, Bunna-s
Viton-a, silicon, TFE
1- large sizes
may require
supports
above or
below the line
if pipe
supports are
inadequate.
1- sleeve
material
2- exposed or
encased sleeve
3- operating
pressure
4- operating
temperature
32
Valves
Classification
Pinch
Valve
33. Definition Recommended Application Advantages Variations Materials Special
installation
and,
maintenance
instructions
Ordering
specifications
a relief valve is a
self actuated valve
designed to provide
accurate automatic
pressure
regulation. for non-
compressible fluid
service and opens
slowly as pressure
increases,
regulating the
operating pressure.
safety valve opens
quickly with a pop
action to relieve
excessive pressure
caused by gases or
compressible
fluids.
where a
predetermined
pressure range is
required
1- hot water
2- steam
3- gases
4- vapor
1- inexpensive
2- no auxiliary
power required for
operation
1- safety, safety
relief
2- diaphragm
construction for
valves used in
corrosive service.
body cast iron
,carbon
steel
bronze,
brass,
TFE -lined
stainless
steel.
1- should be
installed in
accordance with
provisions of
ASME unfired
pressure vessel
code.
2- should be
installed in
readily
accessible areas
for inspection
and
maintenance
1- body material
2- seat material
3- operating
pressure.
4- operating
temperature.
trim various
33
Valves
Classification
Relief
Valve
34. Definition Recommended Application Advantages Variations Materials Special
installation and,
maintenance
instructions
Designed to heck
reversal flow.
Fluid flow in the
desired direction open
the valve, reversal of
flow closes it
1- Swing check
2- Lift check
3- Ball Check
Swing
1- where minimum
resistance to flow
is needed.
2- infrequent direction
change .
Lift
1- frequent direction
change .
Swing low
velocity liquid
service.
Lift
steam, air, gas,
water,
Vapor lines with
high flow
velocities
Swing turbulence
and pressure
Within valve are
very low.
Lift
1- min. Travel of disk
for full open position.
2- quick acting
Swing
tilting-disk check
valve.
Lift 1-
three body patterns:
angle,
vertical, horizontal.
2- ball , piston
check, spring-
loaded check, stop
check.
Body Cast iron
,all iron,
bronze,
brass, TFE -
lined
Stainless
steel, forged
steel
Swing
1- in vertical lines,
pressure should
Always be under
seat.
2- if valve fails to
seal, check seating
surfaces.
Lift
1- line pressure
should be under
seat.
2- if back flow
leaks, check disk
And seat.Trim Various
34
Valves
Classification
Check
Valve
Used To
1- Start Or Stop The Flow Of The Medium Through The Process.
2- Hand-operated And Can Be Automated With The Addition Of An Actuator.
3- Pressure-relief Valves Are Self-actuated On-off Valves That Open Only When
A Preset Pressure Is Surpassed.
4- Such Valves Are Divided Into Two Families:
4-1- Relief Valves Are Used To Guard Against Over Pressurization Of A Liquid
Service And,
4-2- safety Valves. Are Applied In Gas Applications Where Over Pressurization
Of The System Presents A Safety Or Process Hazard And Must
1- Allow The Fluid To Flow Only In The Desired Direction.
2- Used To Prevent Backflow Of Fluid, Which Could Damage Equipment "Or
Upset The Process. Such Valves Are Especially Useful In Protecting A Pump
In Liquid Applications Or A Compressor In Gas Applications From Backflow
When The Pump Or Compressor Is Shut Down
-Regulate the flow, temperature, or pressure of the service.
- Can move to any position within the stroke of the valve and hold that
position, including the full-open or full-closed positions. Therefore, they
can act as on-off valves also.
-Hand-operated and can be equipped with actuators .
automatic control valves, sometimes referred to simply as control valves,
-To achieve automatic control, these valves are always equipped with
actuators. Actuators are designed to receive A command signal and
convert it into an specific valve position using an outside power source
(air, electric, or hydraulic), which matches the performance needed for
that specific moment.
Designed For The Majority Of Applications:
- Lower-pressure Ratings (16 To 100 Bar.)
- Moderate-temperature Ratings -50 To 650°f (-46 To 343°c),
- Non Corrosive Fluids, And Common Pressure Drops That Do Not Result In
Cavitation Or Flashing.
- Have Some Degree Of Interchangeability
- Designed For A Single Application That Is Outside Normal Process
Applications.
- Such Valves Usually Handle A Demanding Temperature, High Pressure, Or
A Corrosive Medium.
- Valves Equipped With Special Features To Handle Volatile Applications,
Such As High Pressure Drops That Result In Severe Cavitations, Flashing,
Choking, Or High Noise Levels
- Such Valves May Have Highly Engineered Trims In Globe-style Valves,
Or Special Disks Or Balls In Rotary Valves To Either Minimize Or Prevent
The Effects Of The Application.
-The Term Closure Element Is Used To Describe Any Internal Valve Device
That Is Used To Open, Close, Or Regulate The Flow.
- Usually Smaller In Size And Weight Less Than Comparable Linear Valves, Size
For Size. Application Wise, They Are Limited To Certain Pressure Drops And
Are Prone To Cavitation And Flashing Problems.
1- Most Valves Are Designed To Restrict The Flow To Some Extent By
Allowing The Flow Passageway Or Area Of The Closure Element To
Be Smaller Than The Inside Diameter Of The Pipeline.
2- Some Gate And Ball Valves Can Be Designed So That Internal Flow
Passageways Are Large Enough To Pass Flow Without A Significant
Restriction.
3- Full-port Valves Also Allow For The Use Of A Pig In The Pipeline.
1- Closure Elements Restrict The Flow.
2- The Flow Area Of That Port Of The Closure Element Is Less Than The
Area Of The Inside Diameter Of The Pipeline.
3- This Restriction Allows The Valve To Take A Pressure Drop As Flow
Moves Through The Closure Element, Allowing A Partial Pressure
Recovery After The Flow Moves Past The Restriction.
4- The Primary Purpose Of Reduced-port Valves Is To Control The Flow
Through Reduced Flow Or Through Throttling, Which Is Defined As
Regulating The Closure Element To Provide Varying Levels Of Flow At A
Certain Opening Of The Valve.