215 Instructor Guide

7/27/2019 215 Instructor Guide

1/46

215 Valve Selection andMaintenance

Instructor Guide

rwww.training4energy


2/46

.www.training4energy

215-01 Introduction to Valves andTheir Components

esson Overview

ntroduction:lves are the single most common piece o equipment ound in industrial acilities.

though there are many types, shapes, and sizes o valves, they all have the same basic parts. This lesson will describe the

ajor components common to most valves, and will explain the basic types o fow control elements employed in valve

sign.

earning Outcome:hen you complete this lesson, you will be able to explain the basic design and unction o valves, major valve components

d fow control elements.

earning Objectives:Discuss the overall purposes served by valves in a system or process.

Explain how valve stem leakage is controlled.

Identiy the ollowing valve components:

Body

Bonnet

Stem

Actuator

Packing

SeatDisc


3/46


215-01 Introduction to Valves andtheir components

Discussion QuestionsList and describe the 5 basic parts of a valve.

What purposes does the bonnet serve?

Label the given components of this valve.

Bonnet

Disc

Handwheel

Seat

Stem

this valve.

Body - The body is the framework that holds the valve together and is the primary pressure boundary.Bonnet - The bonnet is the cover for the opening in the valve body.

Trim - The trim is the collective name for the internals of the valve.

Actuator - The valve actuator operates the stem and disc assembly.

Packing - Packing prevents leakage from the space between the valves stem and bonnet

1. To serve as a pressure boundary

2. To contain the components of the valve

3. To allow access to the body and component parts

Handwheel

Disc

Seat

Bonnet

Stem


4/46



Discussion QuestionsThe valve actuator operates the ______________________.

a. bonnetb. stem and disc assembly

c. valve packing

d. seal rings

List and describe the 4 methods o controlling fow through valves.

Inormation about the valve that is marked on the outside o the valve is called ______________________.

1. Move a disc or plug into or against an orifce.2. Slide a at, cylindrical or spherical surace against an orifce.3. Rotate a disc or ellipse about a shat extending across the diameter o an orifce.4. Move a exible material into the ow passage.

bridge wall markings


5/46



Additional Hands On Activitiestivity 1 - Examine various valves throughout your facility and compare the functions and uses of each.

tivity 2 - Examine various cutaway or dissectible valves and identify the basic components of each.

Recommended Lab Equipmenttaway or dissectible valves


6/46


215-02 Valve Actuators

esson Overview

ntroduction:we discussed in this modules initial lesson, an actuator is the component needed to position a valves stem and disc

sembly. In some designs, the actuator is supported by the bonnet. In other designs, a yoke mounted to the bonnet

pports the actuator.

peration may be based on a manually operated hand-wheel, a manual lever, a motor operator, a solenoid operator, a

eumatic operator, or a hydraulic ram, depending on the type of actuator.

earning Outcome:hen you complete this lesson, you will be able to discuss the use, selection, and design of various actuators, from simple

anual hand-wheels to relatively complex electrical and hydraulic manipulators.

earning Objectives:Describe the construction and principle of operation for the following types of valve actuators:

Manual

Electric motor

Pneumatic

Hydraulic

Solenoid

Identify several types of valve position indicators.


7/46



Discussion QuestionsIdentiy the secondary wheel on this graphic o a hammer handwheel.

Which o the ollowing is NOT an actuator type?

a. Solenoid actuator

b. Pneumatic actuator

c. Piston wheel actuator

d. Electrical motor actuator

I air pressure opens the pneumatically operated valve and spring action closes the valve, the pneumatic

actuator is termed _________.

a. Direct acting.

b. Reverse acting.

c. Dual acting

d. Proportionally controlled

Explain what is used to position the valve when a duplex actuator is used.

In single solenoid valves, spring pressure acts ________ the motion o the slug when power is applied

to the solenoid.

a. With

b. Against

c. To multiply

d. To channel

The diferential pressure between one side o a diaphragm and the other side o the diaphragm will position the

valve stem.

Secondary Wheel


8/46



Additional Hands On Activitiestivity 1 - Identify a manually actuated valve in your facility.

tivity 2 - Identify a pneumatically actuated valve in your facility.

tivity 3 - Identify a hydraulically actuated valve in your facility.

tivity 4 - Identify an electrically actuated valve in your facility.

tivity 5 - Identify a manually actuated valve in your facility.

tivity 6 - Identify solenoid actuated valve in your facility.

tivity 7- Locate various valve position indicators on valves in your facility. Record the type of indication used

Recommended Lab Equipmentlves with various kinds of actuators: Manual (rising and non-rising stem, hammer wheel) electric,

eumatic, hydraulic, solenoid.


9/46


215-03 Gate Valves

esson Overview

ntroduction:te valves are relatively simple in design and unction. They are used or zero fow and ull fow services, as well as or

olation o fow. Normally, gate valves are placed where straight ree fow is desired, and where an immediate shuto o fo

ay be needed.

earning Outcome:hen you complete this lesson, you will be able to explain the use, selection, and design o a gate valve. You will also be ab

describe how dierent service conditions aect gate valve conguration.

earning Objectives:Describe the operation o a gate valve.

Discuss some advantages and disadvantages o a gate valve.

List various gate valve disc congurations and identiy the conditions under which they are used.

Describe dierent gate valve stem and valve seat designs.


10/46


215-03 Gate Valves

Discussion QuestionsDescribe some advantages o a gate valve.

Explain what is meant when we say that a gate valve is a linear motion valve.

Which o the ollowing is NOT a unction o a gate valve?

a. Isolation o fow

b. Starting fuid fow

c. Stopping fuid fow

d. Regulating fuid fow

What type o gate valve wedge is illustrated in this picture?

Discuss the dierence between a rising stem and a non-rising stem gate valve.

Its disc is completely removed rom the fow stream when the valve is ully open. This characteristic oers virtually

no resistance to fow when the valve is open. Thereore, there is little pressure drop across an open gate valve.

The 360 degree disc-to-seal ring contact surace provides a good seal when the valve is ully closed. Because o the

mating o disc to the seal ring, minimum leakage occurs across the disc when the gate valve is closed.

A linear motion valve is a valve which opens and closes in a straight line motion

A rising stem valve keeps the stem raised out o the fow path when the valve is open, while non-rising stem valves

have the gate travel up and down the stem o the valve on the stem threads as the valve is opened and closed. On a

rising stem valve you can always tell the position o the valve by looking at the stem position outside the valve.

This is a solid wedge design


11/46


215-03 Gate Valves

Additional Hands On Activitiestivity 1 - Identiy a gate valve as rising or non-rising stem design

tivity 2 - Observe the operation o a rising stem valve

tivity 3 - Observe the operation o a non-rising stem valve

tivity 4 - Identiy the stem, seats, disc, actuator, bonnet, and body o various gate valves

tivity 5 - Identiy and observe the operation o a solid wedge designed gate valve

tivity 6 - Identiy and observe the operation o a fexible wedge designed gate valvetivity 7 - Identiy and observe the operation o a split wedge designed gate valve

tivity 8 - Identiy and observe the operation o a parallel disc designed gate valve

tivity 9 - Identiy a machined seat on a gate valve

tivity 10 - Identiy a seat ring constructed gate valve

Recommended Lab Equipmentte valves with various disc and seat congurations. Cutaways o these valves: Solid, fexible, and split wedge; parallel

sc. Rising and non-rising stem gate valves


12/46


215-04 Globe Valves

esson Overview

ntroduction:ost control valves ound in industrial acilities are globe valves. They are primarily used or controlling (throttling) fows in

ping systems.

e seating suraces, body designs, and disc arrangements in globe valves dier according to the design and intended

plication.

earning Outcome:hen you complete this lesson, you will be able to describe the use, selection, and design o globe valves.

earning Objectives:Explain the operation o a globe valve.

Describe the three primary body designs.

Describe the three basic disc designs used in globe valves.

Discuss the advantages and disadvantages o these designs.

Explain how the disc and stems are attached in globe valves.

Describe seating arrangements and direction o fow through globe valves.


13/46


215-04 Globe Valves

Discussion QuestionsWhat is the essential principle o operation and advantage behind a globe valves design?

Match the ollowing globe valve body designs to the correct picture. Z-Body,Y-Body, Angle Body

Which type o globe valve disk design provides the best throttling characteristics?

What type o globe valve stem design has the sic slip on and of o the stem?

Explain the purpose o a backseat in a globe valve.

For low temperature applications, globe valves are ordinarily installed so that ow pressure is ________ the disc.

For high temperature steam service, globe valves are installed so that pressure is _______ the disc.

a. Above; under

b. Under; above

c. Above; parallel to

d. Parallel to; under

The perpendicular movement o the disc toward or away rom the seat is the principle o operation. The movement

causes the space between the disc and seat ring to gradually close as the valve is closed. This characteristic gives th

globe valve the good throttling ability needed to efectively regulate ow.

The plug disc

The T-slot construction design connection

A backseat is a seating arrangement that provides a seal between the stem and bonnet. When the valve is ully

open, the disc seats against the backseat. The backseat design prevents system pressure rom building against

Y-Body Globe ValveAngle Body Globe Z-Body Globe Valve


14/46


215-04 Globe Valves

Additional Hands On Activitiestivity 1 - Identify a Z-body globe valve and its component parts (cutaway)

tivity 2 - Identify a Y-body globe valve and its component parts (cutaway)

tivity 3 - Identify an angle globe valve and its component parts (cutaway)

tivity 4 - Disassemble globe valves of T-slot and disc nut construction

tivity 5 - Identify ball, composition, and plug disc globe valves

Recommended Lab Equipmentobe valves and globe valve cutaways of various designs including: Z-body, Y-body and angle designs; ball, composition

d plug discs; T- nut and disc nut construction stems; various seat designs


15/46


esson Overview

ntroduction:

earning Outcome:

dustrial applications.

earning Objectives:

5


16/46


215-05 Butterfy Valves

Discussion QuestionsDiscuss what is mean by a quarter turn valve

Explain what is mean by a rotary motion valve.

Identiy the butterfy valves stem, disc, and body in this picture o a disassembled butterfy valve.

Discuss the two methods commonly used to secure the disc to the valve stem in a butterfy valve.

What type o butterfy valve is held in place between two pipe fanges, which are joined by bolts that pass through

holes in the valves outer casing?

A quarter turn valve reers to a valve that cam be ully opened or ully closed with a quarter turn o the valves actuat

A rotary motion valve reers to a valve that opens or closes in a circular motion.

In one method the disc is bored through and secured to the stem with bolts or pins. The other method involves

boring the disc as beore, then shaping the upper stem bore to t a squared or hex-shaped stem. This allows the

disc to "foat" and seek its center in the seat.

A lug waer design butterfy valve

Disc

BodyStem


17/46


215-05 Butterfy Valves

Additional Hands On Activitiestivity 1 - Demonstrate opening and closing a butterfy valve

tivity 2 - Disassemble a butterfy valve and identiy the method used to connect the stem to the disc o the valve

tivity 3 - Identiy the components o a butterfy valve including the disc, seat, body, stem, and actuator

tivity 4 - Reassemble a butterfy valve

Recommended Lab Equipmentrious designs o butterfy valves and cutaways o valves: Waer and lug waer design; dierent stem and disk connections;

erent seating arrangements


18/46


215-06 Ball Valves

esson Overview

ntroduction:e ball valve, like the butterfy valve, belongs to the amily o valves called quarter turn valves.

operate it, you turn a handle attached to a ball inside the valve. The ball has a hole, or port, through the middle. When th

rt is in line with both ends o the valve, fow occurs. When the hole is perpendicular to the ends o the valve, fow isocked.

ll valves are excellent or shuto applications. They dont oer the ne control generally necessary or throttling

plications, but are sometimes used or this purpose.

ll valves can be made rom materials that can withstand corrosion and caustics. They are minimal in cost and installation;

ereore they are dominant in chemical uses with low pressure.

earning Outcome:hen you complete this lesson, you will be able to explain the use, selection, and design o ball valves ound in industrial

plications.

earning Objectives:Describe the operation o a ball valve.

Identiy the ball valves advantages and disadvantages.

List the our common ball valve port designs.

List the our general ball valve body styles.

Explain the signicance o valve handle positions on a ball valve.


19/46


215-06 Ball Valves

Discussion QuestionsList some advantages o a ball valve.

List some disadvantages o a ball valve.

What type o port design does the ball valve pictured here have?

a. Full Port

b. Standard port

c. Reduced port

d. V- port

What component o a ball valve is being held in this picture?

a. Stem

b. Ball

c. Bonnet cap

d. Seat

A ball valve is generally the least expensive type o valve and has low maintenance costs.

Ball valves can be turned rom completely on to of very quickly, with a quarter turn o the actuator handle.

Ball valves are compact, require no lubrication, and give tight sealing with low torque.

Conventional ball valves have relatively poor throttling characteristics.

In a throttling position, the partially exposed seat rapidly erodes because o exposure to owing uids.


20/46


215-06 Ball Valves

Discussion QuestionsIs the ball valve pictured here open or closed?

It is open because the valve handle is inline with the valve body


21/46


215-06 Ball Valves

Additional Hands On Activitiestivity 1 - Demonstrate opening and closing a ball valve

tivity 2 - Disassemble a ball valve. and identify its components including, The stem, body, seats, actuator, and ball

tivity 3 - Identify a ball valves components including; the stem, body, seats, actuator, and ball

tivity 4 - Reassemble a ball valve

tivity 5 - Identify ball valves as full, standard, reduced, or V-port design.

Recommended Lab Equipmentarious types of ball valves and cutaways: Full, standard, reduced, and V-port design; split body, end entry, top entry, and

ree piece designs


22/46


215-07 Check Valves

esson Overview

ntroduction:eck valves are designed to prevent the reversal o fow in a piping system.

ow reversal can be controlled by the use o a disc, fapper, or plate rotating into or out o the fowpath o the fuid; an

ernative method employs a disc, piston, or ball moving along the axis o the fuids fowpath.

earning Outcome:hen you complete this lesson, you will be able to explain the use, selection, and design o check valves ound in industrial

plications.

earning Objectives:Discuss the operation o check valves.

Describe the construction o each o the ollowing types o check valves:Swing

Tilting Disc

Lit

Piston

Butterfy

Stop


23/46


215-07 Globe Valves

Discussion QuestionsDiscuss the purpose o check valves.

Which o the ollowing is NOT a way that check valves can close?

a. By fuid backpressure

b. A spring

c. The weight o the check mechanism

d. Solenoid action

Why are swing check valves not recommended or applications where there is a requent reversal o fow?

What type o check valve is shown in this picture?

a. Lit check valve

b. Stop check valvec. Piston check valve

d. Tilting disc check valve

What type o check valve is shown in this picture?

a. Lit check valve

b. Stop check valve

c. Piston check valved. Tilting disc check valve

How should a butterfy valve be correctly installed?

Check valves are used to prevent the backfow o fuids in a piping system

Because the fow reversals will cause the check valves disc to fuctuate rapidly and results in valve chatter.

A butterfy valve must be installed with the fow entering coming rom the hinge post end o the valve


24/46


215-07 Check Valves

Additional Hands On Activitiestivity 1 - Identiy various types o check valves based upon their construction

tivity 2 - Manually operate the various check valves and note the direction o fow through each type o valve

Recommended Lab Equipmentwing check valve, tilting disc check valve, lit check valves, piston check valve, butterfy check valve, stop check valve.taways o valves


25/46


215-08 Needle Valves

esson Overview

ntroduction:needle valve employs a small orifce and a threaded, needle-like plunger to precisely regulate ow. It oers fne control, bu

only capable o handling applications with a relatively small ow.

earning Outcome:hen you complete this lesson, you will be able to use appropriate terms to explain centriugal pump operation.When you

mplete this lesson, you will be able to describe the use, selection, and design o a needle valve.

earning Objectives:Explain the operation o a needle valve.

Describe the construction o a needle valve.

Describe a needle valves body design and discuss how it contributes to its unction.


26/46



Discussion QuestionsIdentiy the needle point on the end o the valve stem in this cutaway picture o a needle valve.

Describe the construction o a needle valve.

Discuss some applications or needle valves.

A needle valve has a relatively small orifce with a long, tapered, conical seat. A needle-shaped plunger, on the

end o a screw, exactly fts this seat. As the screw is turned and the plunger retracted, ow between the seat and

the plunger is possible; however, until the plunger is completely retracted the uid ow is signifcantly impeded.

Since it takes many turns o the fne-threaded screw to retract the plunger, precise regulation o the ow rate is

possible.

Metering, precision components, automatic combustion controls, reducing valves, pump governors.

Needle Point


27/46



Additional Hands On Activitiestivity 1 - Identiy the plunger and seat on a needle valve

tivity 2 - Manually operate a needle valve. Observe the plunger moving in and out o the orifce and seating.

Recommended Lab Equipmentrious needle valve; cutaways o needle valves


28/46


215-09 Plug Valves

esson Overview

ntroduction:cause o its simplicity and compact design, the plug valve is commonly used in industrial acilities. It is easy to operate,

fers positive closure, and can be used or automatic control.

e plug valve unctions under a wide range o temperatures and pressures. It can saely and eciently handle gas and

uid uel, boiler eedwater, condensate, and many other uids.

earning Outcome:hen you complete this lesson, you will be able to describe the use, selection, and design o plug valves commonly ound in

dustrial settings.

earning Objectives:Describe the operation o a plug valve and identiy its advantages.

List the types o plug valve port designs available.

Identiy the advantages and disadvantages o multi-port plug valves.

Discuss the use o lubricated and non-lubricated plug valve design.

Explain proper care o a plug valve gland.


29/46


215-09 Plug Valves

Discussion QuestionsIdentiy the valve plug in this picture.

What is the diference between a ull port plug and a standard port plug?

What type o valve port is preerred i the plug valve is to be used or throttling service?

a. Round port

b. Diamond port

c. Rectangular port

d. Square port

Explain what is meant by a multi port plug valve.

Describe the diference between lubricated and non-lubricated plug valves

I a round port plug is the same size or larger than the pipe's inside diameter, it is reerred to as a ull port plug. I the

opening is smaller than the pipe's inside diameter, the port is reerred to as a standard round port.

A valve design that can divert the ow to diferent ow paths through the valve. This enables the ow to be

diverted rom one line to another.

A lubricated plug valve uses grease on the plug to lubricate the plug and seal the gap between the valves

plug and its body to eliminate leakage. A non-lubricated plug valve uses an elastomer sleeve surround-

ing the plug or liting mechanism to help move the plug.

Valve Plug


30/46


215-09 Plug Valves

Additional Hands On Activitiestivity 1 - Identify the components of a plug valve

tivity 2 - Manually operate a lubricated plug valve

tivity 3 - Manually operate a lift-type plug valve

tivity 4 - Manually operate a sleeve type plug valve

tivity 5 - Manually operate a multiport plug valve

Recommended Lab Equipmentrious types of plug valves and plug valve cutaways. Round, diamond, rectangular, and multi-port plug valves. Lubricated

d non-lubricated plug valves


31/46


215-10 Diaphragm Valves

esson Overview

ntroduction:diaphragm valve has disc and seating suraces made o fexible materials. Diaphragm valves are used in many industrial

plications, but are particularly suited or systems carrying chemicals, harmul gasses, and corrosive materials.

earning Outcome:hen you complete this lesson, you will be able to describe the use, selection, and design o the two basic types o

aphragm valves.

earning Objectives:Discuss the operation o a diaphragm valve.

Describe the construction o the diaphragm.

Explain the use o dierent types o diaphragm valve stem assemblies.

Describe the diaphragm valves bonnet assembly.


32/46



Discussion QuestionsIdentiy the diaphragm and the weir in this cutaway o a diaphragm valve.

What protects the operating mechanism o a diaphragm valve rom damage due to contact with process fuids?

Explain how the valve stem on a diaphragm valve raises and lowers the compressor, when the stem itsel doesnt

rotate.

Which o the ollowing operators (actuators) is not commonly ound on a diaphragm valve?

a. Chain wheelb. Lever

c. Hydraulic

d. Solenoid

The diaphragm itsel seals the operating mechanism rom the process fuid. The fuid is below thediaphragm and the operating mechanism is contained above the diaphragm.

The hand-wheel rotates a stem bushing that engages the stem threads and moves the stem up and down. As

the stem moves, so does the compressor that is pinned to the stem. The diaphragm, in turn, is secured to the

compressor.

DiaphragmWeir


33/46



Additional Hands On Activitiestivity 1 - Identify the weir and operator on a weir type diaphragm valve. Manually operate valve

tivity 2 - Identify the contoured bottom and operator on a straight through diaphragm valve. Manually operate valve.

tivity 3 - Operate an indicating and non- indicating diaphragm valve.

tivity 4 - Observe the replacement of the diaphragm on a diaphragm valve.

tivity 5 - Demonstrate the replacement of a diaphragm on a diaphragm valve.

tivity 6 - Locate and identify diaphragm valves in your facility

Recommended Lab Equipmenteir type and straight through type diaphragm valves. Indicating and non indicating type diaphragm valves. Valve

taways


34/46


215-11 Pinch Valves

esson Overview

ntroduction:nch valves are used in many industrial applications where the corrosiveness o the fuid being handled, or the amount o

ids present in the fuid fow, will prevent other valve types rom working properly.

nch valves allow the operating mechanism o the valve to be isolated rom the process fuid.

earning Outcome:hen you complete this lesson you will be able to describe the use, selection, and design o pinch valves.

earning Objectives:Discuss the operation o pinch valves.

Explain how the pinch valves construction acilitates its unction.

Identiy applications where pinch valves operate most eectively.


35/46


215-11 Pinch Valves

Discussion QuestionsIdentiy the pinching mechanism and the sleeve in this cutaway picture o a pinch valve.

Most pinch valves are supplied with the sleeve (valve body) _________.

a. Exposedb. Collapsed

c. Infated

d. Removed

Explain how a pinch valve can be operated hydraulically or pneumatically.

What tends to happen to exposed sleeve valve in vacuum applications?

Explain how the operating mechanism o a pinch valve is kept out o contact with the fuid fowing through the

valve.

The valve can be operated by manipulating the pressure o a liquid or gas within the metal case to orce the

sleeve walls together

They tend to collapse when vacuum is applied

The operating mechanism is completely isolated because the fuid fowing through the valve is contained entirely

with in the fexible sleeve. The actuator and pinching mechanism works on the outside o this sleeve.

Pinching Mechanism

Sleeve


36/46


215-11 Pinch Valves

Additional Hands On Activitiestivity 1 - Identify the pinching device, actuator, and sleeve on a pinch valve

tivity 2 - Manually operate a pinch valve

tivity 3 - Locate pinch valves installed in your facility

Recommended Lab Equipmentrious types of pinch valves; exposed sleeve and metallic sleeve; hand actuated, pneumatically and hydraulically actuated;

taways of pinch valves


37/46


215-12 Safety and Relief Valves

esson Overview

ntroduction:lves can be used as saety devices to relieve excess pressures in process piping and equipment.

wo types o specialized valves which serve this purpose are saety valves and relie valves.

earning Outcome:hen you complete this lesson you will be able to describe the use, selection, and design o saety valves and relie valves.

earning Objectives:Describe the major diference between saety valves and relie valves.

Explain the principle o operation behind a saety valve.

Explain the principle o operation behind a relie valve.

Describe the use o a pilot operated relie valve.

Explain the principle o operation behind a pilot operated saety valve.


38/46



Discussion QuestionsExplain the major diference in usage between saety valves and relie valves.

Match the ollowing globe valve body designs to the correct picture.

a. Pop open rapidly

b. Gradually open

c. Chatter

d. Not open

Which type o globe valve disk design provides the best throttling characteristics?

a. Pop open rapidly

b. Gradually open

c. Chatter

d. Not open

Explain the reason why a saety valve must be designed diferently than a relie valve.

What mechanism is used in saety valves to achieve the quick popping o the valve?

The major diference is that saety valves are used on gas systems, while relie valves are used on liquid systems.

Because a saety valve relieves gas pressures and a relie valve relieves liquid pressures. The saety valve must

be designed larger and to relieve larger quantities o gas, because a pressurized gas will expand a great deal in

volume when that pressure is reduced upon release. A small amount o liquid relieved rom a relie valve will

quickly reduce system pressure.

The design o the disc. It is designed so that as the disc lits a larger area o the disc comes into contact with

the escaping gas, and thus this gas exerts its orce on a larger area o the disc and quickly causes it to pop

open.


39/46



Discussion QuestionsWhat distinguishes a conventional safety valve from a pilot operated safety valve?

a. Pilot valves use a spring to hold the disc on its seat

b. Pilot valves use counterweights to hold the disc on its seat

c. Pilot valves use compressed air to hold the disc on its seat

d. Pilot valves use system pressure to hold the disc on its seat

Label the dome area on this picture of a pilot operated safety valve.

What typically operates a pilot operated relief valve?

a. A spring

b. A pneumatic latch

c. A solenoid

d. A bellows

Dome


40/46



Additional Hands On Activitiestivity 1 - Locate safety and relief valves in your facility and identify as safety or relief valves

tivity 2 - Manually operate a relief valve

tivity 3 - Manually operate a safety valve

tivity 4 - Identify the components of a conventional safety valve: Inlet; outlet; spring; huddling chamber; disc; adjusting

nut

tivity 5 - Identify the components of a conventional relief valve: Inlet; outlet; spring; disc; adjusting nuttivity 6 - Identify the components of a pilot operated safety valve: Inlet; outlet; pilot tube; piston; seat; dome; control

pilot; spring

tivity 7 - Identify the components of a pilot operated relief valve; Inlet; outlet; disc; seat; pilot tube; pilot valve

Recommended Lab Equipmentfety valves; relief valves; pilot operated safety valves; pilot operated relief valves; cutaways of these valves


41/46


215-13 Solenoid Valves

esson Overview

ntroduction:lenoid valves are electro-mechanical devices that employ a solenoid to control a valves opening and closing motion.

lenoid valves are used to control fuid fows in pneumatic and hydraulic systems. A solenoid valve is typically either all the

ay open or all the way closed, so it is not usually used or modulating control.

earning Outcome:hen you complete this lesson, you will be able to describe the overall design and unction o various solenoid valves.

earning Objectives:Explain the basic principle behind the operation o a solenoid.

Identiy the components o a solenoid valve.

Describe solenoid valve operation.

Compare tape-wrapped and encapsulated coil designs.

Dene the terms normally open and normally closed as they relate to solenoid valves.

Explain the dierence between two-way and three-way solenoid valves.


42/46



Discussion Questions

Identiy the plunger, the coil, and the seat in this cutaway o a solenoid valve.

Discuss the basic operation o a solenoid valve.

Explain what is meant when it is stated that a solenoid valve is NC?

The coils in solenoid valve usually are ___________ or _________ coils.

a. Tape wrapped; glued

b. Molded; tape wrappedc. Glued; molded

d. Soldered; molded

Explain the diference between a two-way and a three-way solenoid valve.

A solenoid consists o a wire coil and a moveable iron core, called a plunger. The plunger moves into and out o the c

When the coil is energized with electrical current, a magnetic eld is created. This eld acts on the plunger; as a resu

the plunger is pulled into the magnetic eld o the coil. In a solenoid valve, the valves plug is held in place by a sprinWhen electric current energizes the solenoid, the current drawn through the solenoids coil generates an electromag

netic orce. This orce, in turn, opposes the spring, causing the valve plug to move. When the current is removed ro

the coil, the spring in the valve returns the plug to its normal position.

A solenoid valve is said to be normally closed (NC) when it does not allow uid to pass through it in its resting posit

(when no current is energizing the coil).

Two-way solenoid valves have two ports, one inlet and one outlet. They have only one orice or controlling uid o

through the valve. Three-way solenoid valves have three ports; one inlet, one outlet, and one exhaust port. A three

way valve has two orices or directing ow through the valve.

Plunger

Seat

Coil


43/46



Additional Hands On Activitiestivity 1 - Identify the major components of a tape wrapped coil type solenoid valve

tivity 2 - Identify the major components of a encapsulated coil solenoid valve

tivity 3 - Dissect and reassemble a solenoid valve.

tivity 4 - Identify the type of power supplied to solenoid valves in your facility

Recommended Lab Equipmentwo-way and three way solenoid valves. Solenoid valve cutaways or dissectible models. Tape wrapped and molded

enoid coils.


44/46


215-14 Valve Positioners

esson Overview

ntroduction:valve positioner is a type o relay that can be used between the valves controller output and the valve diaphragm. The

sitioner increases or decreases the signal operating the valve actuator, helping the valves fnal control element more

curately reach the desired position.

earning Outcome:hen you complete this lesson, you will be able to describe the basic design and unction o common types o valve

sitioners used in industrial acilities.

earning Objectives:Identiy common tasks that might prompt the use o valve positioners.

Describe various types o positioners.

Compare basic operation o the three categories o digital positioners.

Explain how a pneumatic positioner works.

Describe the operation o an electro-pneumatic positioner.


45/46



Discussion QuestionsExplain the need or valve positioners.

Which o the ollowing is NOT a type o valve positioner?

a. Pneumatic

b. Electronic

c. Digital

d. Hydraulic

What type o digital positioner is capable o two way digital communication over the same wires used or the

analog signal?

a. Digital non-communicating

b. HART

c. Fieldbus

d. PERT

From where does the valve positioner receive its input signal?

What type o valve positioner is shown in this picture?

a. Pneumatic

b. Electro-pneumatic

c. Digital

d. Electronic

The use o a valve positioner should be considered when you

need to:

Speed up valve response; a positioner can use higher pressure

and greater air fow to adjust the valve position more quickly. More accurately position the valve.

Increase the pressure that a particular actuator and valve can

close against.

Prevent riction in the valve (especially the

packing) that would cause unacceptable

hysteresis. Make a non-linear actuator perorm linearly.

Prevent varying dierential pressures within th

fuid rom varying the plug position.

It receives the signal rom the controller (the controller output)


46/46



Additional Hands On Activitiestivity 1 - Identiy location and type o valve positioners used in your acility

tivity 2 - Determine the input and output signals to a valve positioner

tivity 3 - Observe the action o a valve positioner at diferent controller output signals

Recommended Lab Equipment:ntrol loop trainer with positioner; pneumatic, electro-pneumatic, electronic, and digital positioners

Documents

215 Instructor Guide