Valves_Control valve_Actuators.ppt

1
VALVES
CONTROL VALVES,
SOLENOIDS and ACTUATORS

2
Introduction
INSTRUMENTATION - VALVES
What is a valve?
Any device for closing or modifying the
passage through a pipe, outlet, inlet or the
like, in order to stop, allow, or control the
flow of a fluid media.
…..continued

3
Introduction
This presentation explains:
1- The main 9 types of valves used in the
Petrochemical industry. Such as; Globe Valve,
Butterfly Valve, Diaphragm Valve, Gate Valve,
etc.
2- What is an Actuator:
Air, fluid-powered or electrically powered device
that supplies force and motion to a VALVE
CLOSURE MEMBER. Called an Actuator
…..continued

4
Introduction
3- Control Valves:
Process plants consist of hundreds, or even
thousands of control loops, all networked
together to produce a product to be offered for
sale. Each of these control loops is designed to
keep some important process variable such as
pressure, flow, level, temperature etc. within a
required operating range to ensure the quality of
the end product. Here the control valves job come
and that is the importance of control valves.
…..continued

5
Introduction

6
Agenda
Day 34 Introduction to control valves
Day 35 Types of Valves and their operation
Day 36
Advantages, disadvantages, selection
and specifications for valves
Day 37 Actuators, Solenoids and Positioners
Day 38 Revision & Exam

7
• State the three main reasons for
controlling fluids.
• Identify different types of control valve.
• Know the specific uses of various
valves.
• Select appropriate valves for specific
tasks.
Learning Objectives
The trainee will:
…..continued

8
• Understand the valve specification and
selection requirements.
• State the advantages and disadvantages
of a variety of different valves.
• State the purpose and use of actuators.
• State the purpose and use of
positioners.
Learning Objectives
The trainee will:

9
What is a Control Valve?
Valves are the most common components in process piping systems.
They are the main method of fluid (liquid & gas) control for:-
Flow
Pressure
Direction
…..continued

10
> Valves may be required to operate continuously e.g. control valves.
> They may be operated intermittently e.g. isolation / stop valves.
> They may be installed to operate rarely e.g. safety valves.
> A valve can be a very simple, low cost item or it may be a very
complicated, expensive item.

11
1. Valves are selected for their:-
> Ability to throttle flow
> Lack of turbulence or resistance to flow when fully open
> Quick opening and closing mechanism
> Tight shut off
> Ability to allow flow in one direction only
> Opening at a preset pressure for pressure control
> Ability to handle abrasive substance without rapid wear.

12
2. Flow Regulation / Throttle Valves
Many applications require the flow of the fluid to be regulated
(throttled) at some fixed level between zero and maximum
flow limits.
Valves used for this job include globe valves, needle valves &
butterfly valves.

13
3. Pressure Regulation
> In many applications, especially with gases, there is a need
to reduce the supply pressure to a set fixed value.
> It may also be necessary to maintain this reduced pressure
over a range of fluid flow conditions.
> The pressure regulator valve (which has a globe valve
design) is used for this job.

14
4. Non-Return or Check Valves
> In some circumstances it is important to prevent
reversed fluid flow.
> The type of valve used for this job is called a non-
return-valve (NRV) or check valve.
> Three main valve types are used for this job:
Lift Check valve
Swing Check valve
Ball Check valve

15
5. Pressure Relief Valves
> Pressure Relief Valves (PRV) are used in liquid service
applications to relieve excess pressure in the system.
> All closed vessels where pressure could build up are
protected by a Pressure Relief Valve.
> An important part of the relief valve installation is the routing
of the relieved fluid.
> Normally relieved fluid is returned to a service tank or
unpressurised part of the system.
> Return lines must always be kept open.

16
6. Pressure Safety Valves
> Pressure Safety Valves (PSV) are used in gas service
applications where too much pressure in the system
can cause damage or a safety risk.
> Valves used for safety applications require regular
inspections to check the settings and the operation.
> The gas released from a PSV normally goes to the
flare.
INSTRUMENTATION -VALVES

17
7. Isolation/Stop Valves
Valves used for this job include gate valves, globe valves,
ball valves, plug valves & diaphragm valves.
The isolation of the downstream system from the upstream
system by use of an isolation or stop valve is a very
important function.
The main requirements of these valves are:-
> tight shut off when closed
> minimum restriction to flow when open

18
8. Valve Specifications and Selection
Specifications to consider when selecting valves are;-
> Diameter
> Working pressure
> Operating temperature
> Type of fluid
> Valve material i.e. brass, bronze, copper, cast
iron, ductile iron, stainless steel, plastics
Continued…….

19
9. Valve Specifications and Selection
> End configuration i.e. threaded, socket weld, butt
weld, push on, soldered ends, clamp, grooved,
flangeless, lugged, mechanical joint or flanged
> Valve actuation method i.e. electric, pneumatic,
hydraulic or manual.
> Seat features i.e. metal to metal, o-ring, soft seat.
Continued…….

20
10. Valve Specifications and Selection (continued)
> Valve class i.e. class IV, V or VI, ANSI standards,
MSS specifications, UL listings, ASME standards,
and federal specification WW-V-35C.
> Applications i.e. petrochemical, chemicals,
general purpose, different oils or fuels, sanitary,
wastewater, water, fire service, refrigeration,
laboratory, medical or cryogenic.

21
What three things can a valve control ?
1. Pressure
2. Flow
3. Direction
Flash Card

22
Name three valves that can be used for throttling flow ?
1 Needle valve
2 Globe valve
3 Butterfly valve
Flash Card

23
Name three valves that can prevent non return of a
fluid down a pipeline?
1. Lift Check Valve
2. Swing Check Valve
3. Ball Check Valve
Flash Card

24
Which one of the following valves is NOT a
stop/isolation valve?
1. Gate
2. Plug
3. Ball
4. Diaphragm
5. Globe
6. Needle
The Needle Valve is NOT a stop or isolation valve
Flash Card

25
Name one valve that rarely operates when in
normal service?
Pressure Relief Valve
Flash Card

26
State ten considerations when selecting a valve for
use?
1. Diameter
2. Pressure
3. Temperature
4. Type of fluid
5. Valve material
6. End configuration
7. Actuation
8. Seating
9. Class of valve
10. Application
Flash Card

27
PLUG VALVE
TYPES OF VALVES

28
TYPES OF VALVES
PLUG VALVE

29
PLUG VALVE
Advantages:
 Cheap
 Offer low resistance to flow when fully open
 Open and close quickly
 Give a tight seal with pressures up to 200 bar
Disadvantages:
 The plug valve is mainly an on/off valve and is not
particularly good for precise regulation
 Despite lubrication, the plug valve has a tendency to bind
(stick)
TYPES OF VALVES

30
BALL VALVE
TYPES OF VALVES

31
BALL VALVE
OPEN CLOSED
TYPES OF VALVES

32
BALL VALVE
(Sectional Plan
View)
TYPES OF VALVES

33
BALL VALVE
Advantages:
Low pressure drop when open
Can be used for gas, liquids or slurries
Open and close quickly and easily
Require no lubrication
Are suitable for handling corrosive fluids
INSTRUMENTATION VALVES
TYPES OF VALVES

34
BALL VALVE
Disadvantages:
 Standard Ball Valve not suitable for
regulating flow
 Not suitable for tight shut-off
 Can be damaged & jammed by solids
INSTRUMENTATION VALVES
TYPES OF VALVES

35
GATE VALVE
> Gate valves are probably the most widely used
valve type in the Petrochemical / refining
industry
> There are two main types of gate valve:
1. Rising stem
2. Non-rising stem
TYPES OF VALVES

36
GATE VALVE
(RISING STEM)
TYPES OF VALVES

37
GATE VALVE
(RISING STEM)
Gate Valve (Rising Stem)
TYPES OF VALVES

38
GATE VALVE
(RISING STEM)
TYPES OF VALVES

39
GATE VALVE
(RISING STEM)
In the rising stem gate valve
the threaded (screwed) part
of the stem is outside of the
valve.
The position of the rising
stem shows if the valve is
open or closed.
TYPES OF VALVES

40
GATE VALVE
(RISING STEM)
OPEN CLOSED
TYPES OF VALVES

41
GATE VALVE
(NON-RISING STEM)
In the non-rising stem
gate valve the threaded
(screwed) part of the
stem is inside the valve.
It is difficult to see if the
valve is open or closed.
TYPES OF VALVES

42
GATE VALVE
(NON-RISING STEM)
TYPES OF VALVES

43
GATE VALVE
Advantages:
 Low pressure drop when fully open
 Offer reasonable flow-rate regulation
 Cheap to manufacture
 Very robust (strong) construction
Disadvantages:
 Sediment or dirt may stop the gate closing fully
 The base of the gate is liable to wear by erosion if operated
partly open
 The gate valve is difficult to operate when opening or
closing against fluids at a very high pressure.
TYPES OF VALVES

44
GLOBE VALVE
TYPES OF VALVES

45
GLOBE VALVE
Globe Valve
TYPES OF VALVES

46
GLOBE VALVE
OPEN CLOSED
TYPES OF VALVES

47
GLOBE VALVE
Advantages:
 Good flow regulation
 Positive shut-off
 Can be used in high pressure systems where positive shut-
off is essential for safe operation
Disadvantages:
x high pressure drop even when the valve is fully open
x The valve seats can be damaged and jammed by solids
TYPES OF VALVES

48
DIAPHRAGM VALVE
TYPES OF VALVES

49
DIAPHRAGM VALVE
Advantages:
 Fairly cheap and easy to make
 Provide good flow regulation
 Maximum wear is located at the diaphragm which is easy
to change
Disadvantages:
X Cannot be used at very high pressures, due to the
weakness of the diaphragm
X They produce a pressure drop when open
TYPES OF VALVES

50
NEEDLE VALVE
Needle valves are used to
give fine, accurate control of
flow.
The 'needle' shaped closing
element is long and comes
to a point.
The seat is also very small.
The stem threads are close
together (a fine thread)
which makes very small
adjustment of the flow
possible.
TYPES OF VALVES

51
NEEDLE VALVE
Needle Valve
TYPES OF VALVES

52
NEEDLE VALVE
Advantages:
 Suitable for regulating flow
 Fine control in small diameter piping
 Tight shut-off
Disadvantages:
X Only for clean fluids
X Can only be used with low flows rates
X High pressure drop when open
TYPES OF VALVES

53
BUTTERFLY VALVE
OPEN CLOSED
WAFER TYPE
BUTTERFLY
VALVE
TYPES OF VALVES

54
BUTTERFLY VALVE
TYPES OF VALVES

55
Butterfly Valve
TYPES OF VALVES
BUTTERFLY VALVE

56
BUTTERFLY VALVE
Advantages:
 The valve can be part open in any position from fully closed
to fully opened.
 Fast operation - the valve moves from full close to full open
in a quarter of a turn
 The handle shows if the valve is open or closed.
 They can receive flow from both sides.
Disadvantages:
X Can only be used with low flows rates
X Not suitable for tight shut-off
TYPES OF VALVES

57
NON RETURN (NRV) or CHECK VALVES
Non Return Valves (NRV) and Check Valves only allow flow in one
direction.
There are several different designs.
The following slides show the three main types:
> BALL CHECK VALVE
> SWING CHECK VALVE
> LIFT CHECK VALVE
TYPES OF VALVES

58
BALL CHECK VALVE
OPEN CLOSED
TYPES OF VALVES

59
SWING CHECK VALVE
TYPES OF VALVES

60
SWING CHECK VALVE
OPEN CLOSED
TYPES OF VALVES

61
SWING CHECK VALVE
Swing Check Valve
TYPES OF VALVES

62
LIFT CHECK VALVE
OPEN CLOSED
TYPES OF VALVES

63
PRESSURE RELIEF VALVE (PRV)
(Review)
> Pressure Relief Valves (PRV) are used in process
applications to relieve excess pressure in the system.
> All closed vessels where pressure could build up are
protected by a Pressure Relief Valve.
> An important part of the relief valve installation is the routing
of the relieved fluid – Normally relieved fluid is returned to a
service tank or unpressurised part of the system.
> Return lines must always be kept open.
TYPES OF VALVES

64
PRESSURE
RELIEF VALVE
(PRV)
TYPES OF VALVES

65
PRESSURE
RELIEF VALVE
(PRV)
TYPES OF VALVES

66
PRESSURE RELIEF
VALVE (PRV)
TYPES OF VALVES

67
TYPES OF VALVES
PRESSURE RELIEF
VALVE (PRV)

68
PRESSURE SAFETY VALVE (PSV)
(Review)
> Pressure Safety Valves (PSV) are used in gas service
applications where too much pressure in the system can
cause damage or a safety risk.
> Valves used for safety applications require regular
inspections to check the settings and the operation.
> The gas released from a PSV normally goes to the flare.
TYPES OF VALVES

69
TYPES OF VALVES
PRESSURE SAFETY
VALVE (PSV)

70
PRESSURE SAFETY
VALVE (PSV)
Steam Boiler
Safety Valve
TYPES OF VALVES

71
A bursting disc is a
non re-usable device
that is designed to
burst or rupture at a set
pressure, thus
protecting process
equipment from high
pressure or vacuum.
PRESSURE SAFETY – BURSTING DISCS
TYPES OF VALVES

72
TYPES OF VALVES

73
TYPES OF VALVES

74
TYPES OF VALVES

75
SOLENOID VALVES
Solenoid controlled valves are the most frequently used in
controlling fluids.
The task of a solenoid valve is to:-
> Shut off flow
> Release fluids
> Dose
> Distribute fluids
> Allow mixing of fluids
TYPES OF VALVES

76
SOLENOID VALVES
Advantages
 High reliability
 Fast, safe switching
 Long service life
 Low control power
 Compact design
Disadvantage
x Requires an electrical supply
TYPES OF VALVES

77
This solenoid valve is an
electro-mechanical valve
(used with liquids or
gases) controlled by
operating an electrical
current through a
solenoid (coil of wire).
SOLENOID VALVES
TYPES OF VALVES

78
Types of Solenoid Valve
> Electromechanical solenoid
An electromagnetic inductive coil wound
round a movable steel armature moves to
provide a mechanical force to the valve.
SOLENOID VALVES
TYPES OF VALVES

79
> Pneumatic solenoid
These are switches which route air to a
pneumatic device (actuator). The moveable
solenoid channels the gas to an appropriate
port.
> Hydraulic solenoid
Similar to pneumatic solenoids except they
control the flow of hydraulic fluid.
SOLENOID VALVES
TYPES OF VALVES

80
ACTUATORS
System actuators use
hydraulic, electronic and
pneumatic input signals to
help activate process control
equipment. Actuators are a
type of transducer or device
that turns signals into physical
motion.
TYPES OF VALVES
Electronic Actuator

81
MANUAL ACTUATOR
This type of actuator
does not require an
outside power source.
They use a hand wheel
or lever to drive a series
of gears.
TYPES OF VALVES

82
PNEUMATIC VALVE
ACTUATOR
Pneumatic valve
actuators adjust valve
position by converting air
pressure into linear or
rotary motion.
TYPES OF VALVES

83
PNEUMATIC VALVE
POSITIONER
Valve positioners
compare a control
signal to a valve
actuator’s position and
move the actuator. They
are used with both
linear valves and rotary
valves.
TYPES OF VALVES

84
Name eight types of valves used in the Petrochemical
industry?
1. Pressure Relief Valve
2. Globe Valve
3. Butterfly Valve
4. Diaphragm Valve
5. Gate Valve
6. Ball Valve
7. Plug valve
8. Needle Valve
Flash Card

85
Control Valve Operation.
Complete the following statement:-
1. Some advantages of using a Solenoid Valve
are:-
high ______________ , fast and _______
switching,
________ service life,
_____ control power,
___________ design,
Flash Card
reliability safe
long
low
compact

86
Control Valve Operation.
Complete the following statement:-
1. Actuators are a type of transducer that turns
____________ into ____________ motion.
Flash Card
signals physical

87
Flash Card
Name these valves.
Ball Valve
Butterfly Valve
Safety Relief Valve
Control
Valve
1 2
3
4

88
Flash Card
1. What does PRV stand for?
Pressure Relief Valve
2. Where are PRV’s used ?
Closed vessels e.g. Boiler

89
Flash Card
1. What does SRV stand for?
Safety Relief Valve
2. What are SRV’s used for ?
Relieve excess pressure and eliminate
the risk of damage.

90
Flash Card
What is the main reason for fitting ball
check valves, swing check valves and lift
check valves ?
To provide a one-way flow and non-return of
fluid up the pipeline.

91
Summary
• Function of Control valves
- flow, pressure and direction
• Valve specifications and selection
- Swing check valve
- Lift check valve
- Pressure reducing valve
- Pressure safety valve
- Bursting discs
- Solenoid valves
- Actuators
- Valve positioners
- Plug valve
- Ball valve
- Gate valve
- Globe valve
- Diaphragm
- Needle valve
- Butterfly valve
- Ball check valve
• Types of Valves, operation, advantages and disadvantages
• Solenoid valves, actuators and positioners

Valves_Control valve_Actuators.ppt

More Related Content

What's hot

Similar to Valves_Control valve_Actuators.ppt

More from KAhmedRehman

Recently uploaded

Valves_Control valve_Actuators.ppt