Valves

Front 1

These devices can start, stop and regulate the volume of flow, prevent fluids passing the wrong way through a pipeline system (backflow) and regulate to relieve pressure.

Back 1

Valves

Front 2

These valves have a tapered or non-tapered plug running vertically through the body of the valve

Back 2

Plug valves

Front 3

Plug valves are generally considered to be quarter turn valves, which means?

Back 3

The tapered plug can only be turned 90deg to stop or start flow through the pipe

Front 4

What are valves used to control

Back 4

The flow of the fluids through the pipe network

Front 5

What is are slurries?

Back 5

Liquids containing suspended solids

Front 6

What are some applications plug valves can be used in

Back 6

Gas and liquid fuel

Extreme temperatures

Liquids containing slurries

Front 7

What plug valve designs allow for less piping and fewer valves to control direction of flow

Back 7

Multi-port design

Front 8

Which plug valves require powered actuators

Back 8

4" NPS and over

Front 9

Name 3 advantages of plug valves

Back 9

1. Simple design with few parts

2. Quick to open or close

3. They can be serviced in place

Front 10

Why do plug valves require more force to turn

Back 10

High friction between the plug and the valve barrel

Front 11

What is more expensive? The plug valve or ball valve?

Back 11

Plug Valve

Front 12

These valves are recommended to be used in the fully open or fully closed position and should never be used to throttle the flow of liquids

Back 12

Gate Valves

Front 13

Why should you not have a slightly open position on a gate valve

Back 13

It will cause high velocity flow through the valve and enhance wire drawing and erosion on the disc and the valve seating

Front 14

This valve is good for being shutoff for long periods of time

Back 14

Gate Valves

Front 15

The gate valve minimizes the pressure drop in this position

Back 15

Fully open position

Front 16

Why are gate valves good for applications involving slurries and viscous liquids

Back 16

The gates knife can cut right through the slurry

Front 17

These valves are used in vacuum system designed for material transport

Back 17

Gate Valves

Front 18

These gate valves are slow opening and slow closing valves

Back 18

Threaded stem gate valve

Front 19

Name a disadvantage of gate valves

Back 19

They are not optimal in applications that require cleanliness or sanitary conditions

Front 20

Why do rising stem gate valves require extra clearance above the valve stem

Back 20

To allow room for the stem to project to it's full length when the valve is open

Front 21

These valves are not recommended where shock loading may occur

Back 21

Gate valves

Front 22

What applications are globe valves installed in

Back 22

Throttling applications

Front 23

How many turns does he fluid need to make to get through the globe valve

Back 23

Nearly 4, 90deg turns

Front 24

What is an advantage of globe valves

Back 24

The require fewer turns to open and close

Front 25

What configurations are globe valves available in?

Back 25

Straight, Y and angle

Front 26

What are self-scouring seats designed for on Y and angle pattern globe valves

Back 26

Use in blow off or blowddown service where mud or sludge has to be removed from a vessel

Front 27

What are the disadvantages of globe valves

Back 27

1. They have a high-pressure drop compared to valves with a straigh-through flow pattern

2. They need greater force to hold the disc against the seat when the line pressure is working to push the disc open

Front 28

Is it hard to machine or resurface valve seats and to replace the disc or seats in the appropriate valve models

Back 28

No, its easy

Front 29

How do ball valves differ from plug valves

Back 29

The ball valve uses a spherical ball that seats against seating rings

Front 30

What is a similarity of ball valves and plug valves

Back 30

They both only require a 90deg turn to open and close it

Front 31

Which are smaller, ball valves or gate valves?

Back 31

Ball valves

Front 32

Name 3 advantages of ball valves

Back 32

1. Provide bubble tight closure

2. Quick to open or close

3. Can be used in both clean fluids and in slurry applications

Front 33

What does a multi-port ball valve design allow for?

Back 33

Less piping and fewer valves to control direction of flow

Front 34

Which require least amount of force to actuate the valve. Ball, gate or glove valve?

Back 34

Ball valve

Front 35

Name the disadvantages of ball valves

Back 35

1. They are not suitable for sustained periods of throttling

2. Sharp particulate matter can settle or be trapped in the body cavities and wear, leakage or valve failure

Front 36

Why are ball valves becoming the most common valve used in all flow control applications today?

Back 36

Because of its laminar flow conditions and operation capabilities

Front 37

Although the two valves are similar. What is the difference between butterfly and gate valve?

Back 37

The butterfly valve disc rotates in the bore of the valve

Front 38

What sizes are gate valves available in

Back 38

1-1/2" to 200"

Front 39

T/F. Butterfly valves are compact and require minimum space for installation in a line?

Back 39

True

Front 40

What is the turn capability of the butterfly valve

Back 40

1/4 turn

Front 41

When to butterfly valves achieve 100% shutoff

Back 41

When the disc is at right angles to the flow of fluids

Front 42

These valves discs are designed for throttling and offer little or no resistance when full open

Back 42

Butterfly Valve

Front 43

What angles are throttling applications restricted to on butterfly valves

Back 43

Between 30 and 80 degree disc openings

Front 44

What are butterfly valves prone to when used for throttling

Back 44

Cavitation or choked flow

Front 45

What is the check valve used for

Back 45

To prevent backflow or reverse flow within the piping system.

Front 46

What does the check valve rely on to close

Back 46

Pressure, gravity and the weight of the disc

Front 47

How does the check valve work

Back 47

The proper direction of flow opens the valve and a reverse direction of flow forces the valve closed. The valve will reopen when the flow return to normal

Front 48

This type of valve does not have a stuffing box

Back 48

Diaphragm valve

Front 49

What does a diaphragm valve use to seal the fluids from the valve stem

Back 49

A flexible diaphragm

Front 50

Why do diaphragm valves have a good chemical resistance

Back 50

Large variety of materials available for the liners and diaphragm

Front 51

What are straight through type of diaphragm valves excellent for?

Back 51

Use with sludge, slurries and other viscous fluids

Front 52

What is the Wier design diaphragm valve best used for

Back 52

General-use applications or for tough corrosive and abrasive services

Front 53

What are diaphragm valves suitable for

Back 53

Hazardous chemical and radioactive fluid services.

Food processing, pharmaceutical and other material processing where atmospheric contamination cannot be allowed

Front 54

What might Weir-type diaphragm valves prevent

Back 54

Drainage of the piping

Front 55

When my diaphragm erode quickly on a diaphragm valve

Back 55

If used for severe throttling of sludge or slurries

Front 56

Why are design variation required for valves.

Back 56

Specific application requirements, space limitations, contents being carried within the piping or desired flow characteristics within the piping system

Front 57

Plug valves have long been associated with this aspect of the industry

Back 57

Gasfitting aspect

Front 58

This variation of plug valve can be locked in the off position

Back 58

Lockable service valve and insulated service valve (luboseal)

Front 59

Where is the lockable service valve put on the natural gas service line.

Back 59

Upstream of the meter

Front 60

What is the most common gas valve used today on an outside installation

Back 60

Insulated Service Valve (Luboseal)

Front 61

What is the insulated union attached to the Luboseal valves purposes

Back 61

1. Provides a barrier between the underground and building piping

2. It provides a method for 2 piping systems to attach together

Front 62

The gas code requires that all appliances must be furnished with this.

Back 62

A gas valve

Front 63

What is a gas valve normally made from

Back 63

Yellow brass

Front 64

This valve is used on gas appliances as a firing valve between the gas controls and the gas burner or as an appliance valve ( before the gas controls)

Back 64

Firing valve or appliance valve

Front 65

The pilot valve is a....

Back 65

Small sized valve used on pilot gas supplies

Front 66

What type of thread is the inlet on a corporation stop valve

Back 66

AWWA thread

Front 67

What is the outlet of the corporation stop valve

Back 67

Flared union got copper water tube

Front 68

What most corporation valves be made of

Back 68

Red brass or bronze

Front 69

Where is the curb stop installed

Back 69

The private property boundary line

Front 70

What is similar to a gas valve but used as a balancing control on hot water heating systems

Back 70

Square-headed steam cock valve

Front 71

These valves have one threaded end and the other is for rubber hose connections

Back 71

Pet cock valve

Front 72

What is the most important variation in the gate valve design

Back 72

The type of disc that is used

Front 73

What are the 4 main types of disc designs for gate valves

Back 73

1. Solid wedge disc

2. Flexible wedge disc

3. Split wedge disc

4. Double disc

Front 74

What is the most widely used gate valve

Back 74

The solid wedge disc valve

Front 75

What is the solid wedge disc valve suitable for

Back 75

Steam, hot and cold water, oil, air or gas service conditions

Front 76

Why is the the solid wedge disc valve ideal for turbulent flow condition?

Back 76

There are no loose internal parts to vibrate and wear.

Front 77

Why do use the flexible wedge disc instead of the solid wedge disc valve

Back 77

The solid wedge disc valve pinches in the closed position due to the valve body contracting more than the disc in cool conditions

Front 78

What gives the flexible wedge disc that degree of flexibility

Back 78

Its hollow around the edges and solid across the centre portion

Front 79

The gate valve disc variation consists of two pieces that sit between two matching tapered seats in the body

Back 79

Split wedge disc

Front 80

What is used to open and close the split wedge disc gate valve

Back 80

A simple spreader mechanism

Front 81

What is the split wedge disc gate valve most suited for

Back 81

Service conditions where laminate flow of the fluid is prevalent

Front 82

Where should split wedge gate valves not be used

Back 82

Where there is a turbulent flow or fluid as the vibrations will wear the internal mechanisms

Front 83

In this valve the disc and seat are parallel to each other and are not tapered

Back 83

Double disc valve

Front 84

When the double disc gate valve is open this happens

Back 84

The spreader mechanism releases its pressure and the two discs move away from the seats before they start to rise

Front 85

What is the other version of gate valve that opens and closes quickly

Back 85

Quick opening gate valve

Front 86

Why use straight patter globe valve on a straight run instead of a gate valve

Back 86

More flow restriction

Front 87

What are straight patter globe valves specifically used for

Back 87

Adjustment or throttling of flow

Front 88

Where is an angle pattern globe valve used

Back 88

Where the pipe turn through 90deg

Front 89

Where are Y pattern globe valves used

Back 89

Straight runs of pipe where the pressure loss must be kept to a minimum or where there is a possibility of sediment being deposited in the line upstream of the valve (steam boiler blow downs)

Front 90

Where are Y pattern globe valves used

Back 90

Straight runs of pipe where the pressure loss must be kept to a minimum or where there is a possibility of sediment being deposited in the line upstream of the valve (steam boiler blow downs)

Front 91

What are 4 main types of globe valve seats and disc designs

Back 91

1. Plug disc valve

2. Conventional disc valve

3. Composition discs

4. Needle valves

Front 92

What are the flow patterns of these valve types

Back 92

Front 93

what is an actuator

Back 93

a device that operates a valve. It is designed to open, close or regulate flow through a valve that is difficult to turn with a normal handle or in a location that is difficult to reach

Front 94

what is a sprocket and chain actuator used for

Back 94

convenient, remote operation of gate or globe valves in overhead locations that are not easily accessible

Front 95

this manual actuator is a gear arrangement that provides a mechanical advantage which allows for easy opening and closing of the valve

Back 95

Bevel and Spur Gearing

Front 96

Can actuators be power actuated

Back 96

yes

Front 97

what does the valve comprise of?

Back 97

the body

the bonnet (cover)

the disc

the pressure-sealing connection between the body and the bonnet

Front 98

what does the valve body do

Back 98

directs the fluid flow through the valve and provides the mountings for internal parts of a valve

Front 99

what is mounted onto the valve body to complete the pressure casing

Back 99

the valve bonnet

Front 100

for these valves the bonnet houses and opening through which the valve stem passes

Back 100

gate, globe, stop check and diaphragm valves

Front 101

what might the valve bonnet have to prevent the process fluid from migrating out along the valve stem

Back 101

a stuffing box or packing gland area

Front 102

what are mounted on the valve bonnet

Back 102

the upper works, such as the yoke or other operating mechanisms that acts to move the valve stem

Front 103

what is the most common design for bonnets used on larger high pressure valves

Back 103

the bolted bonnet

Front 104

what does the valve disc do

Back 104

controls the flow through the valve body

Front 105

why is the disc considered part of the pressure casing

Back 105

because it is under the same line pressure as the valve body and then bonnet when the valve is in the closed position

Front 106

how does water run through a ball valve

Back 106

a hole is drilled through the centre of the ball and a slot is cut into one side of the ball at 90deg to the run of the hole to rotate the ball

Front 107

what is a trunnion ball valve

Back 107

uses a cylinder shape on opposite sides on the that mount the ball with a set of bearings, reducing the thrust required to rotate the ball

Front 108

what are the 3 main parts of the plug valve

Back 108

1. body

2. cover

3. plug

Front 109

what does rectangular port mean

Back 109

the valves have rectangular ports through the plug and body.

Front 110

when talking about 100% area or full port what does it mean

Back 110

the area through the valve is equal to or greater then the area of standard pipe

Front 111

standard opening means?

Back 111

the area through the valve is less than the area of standard pipe. these valves should only be used where restriction of flow is unimportant

Front 112

when the valve has a full round opening through the plug and body, of the same size and area as standard pipe it is refered to as?

Back 112

round port

Front 113

this valve uses a tapered plug with mechanical lifting device that unseats the plug before it is turned to reduce the operating torque required, Or, it may have an elastomeric sleeve or plug coating with a low coefficient of rubbing friction

Back 113

non-lubricated plug valves

Front 114

this actuator is used for service where the valve is normally in the open position

Back 114

air-to-close actuator

Front 115

what is the valve trim

Back 115

the seats, discs, glands, guides, spacers, bushings and springs used inside some valve models that are replaceable

Front 116

T/F. Valve trim is made from the same material as the body, bonnet, stem or packing

Back 116

False, different items of trim are subject to different forces and condition, so different material is needed to accomodate

Front 117

What is the name of a type of needle valve used on steam boilers to determine the water level in the event that the gauge glass is damaged?

Back 117

try cocks

Front 118

what is the simplest variation of sealing the perimeter of the butterfly disc in its closed postion

Back 118

use an elastomer-lined bore that is an interference fit on the disc

Front 119

this the connecting component between the valve actuator and the valve disc

Back 119

the valve stem

Front 120

what is the mechanism that causes the valve stem to move in a valve referred to?

Back 120

the operator

Front 121

what is the backseating feature on a valve stem

Back 121

a marking on the disc face that the valve is in the full open position

Front 122

what is put on a valve stem so the position of the valve can be viewed from a considerable distance

Back 122

brightly coloured plastic caps

Front 123

what is the inside screw rising stem used in the construction of

Back 123

small globe valves

Front 124

what is the major variation between stop check valves and regular globe valves

Back 124

there is no connection between the end of the valve stem and the disc on the check valve

Front 125

this valve stem is used with linear action pneumatic or hydraulic actuators on control valves

Back 125

sliding valve stems

Front 126

this valve stem is used with ball, plug and butterfly valves

Back 126

rotary valve stem

Front 127

what is recommended as part of the valve installation by the manufacturer

Back 127

the valve be run through a full open and close cycle after installation in the line

Front 128

how should the butterfly and ball valve stem be installed as per manufacturer recommendation

Back 128

in the horizontal position6

Front 129

what is the general practice for mounting globe valves

Back 129

the valve stem in the vertical position, with inlet flow pushing the valve up from the seat

Front 130

which direction are check valves installed

Back 130

the flow arrow pointing in the direction of system flow

Front 131

these check valves are used in low-pressure liquid and gas services

Back 131

folding disc check valves

Front 132

what is the similarity of operation of a diaphragm and pinch valve

Back 132

both depend on an external force to collapse and squeeze the outside of the walls of the flow passage together to cause a closure

Front 133

what is linear motion

Back 133

valves move in a straight line to start, stop or throttle flow

Front 134

what is rotary motor

Back 134

valves have closure members that move along an angular or circular path

Front 135

rotary motion valves that require only a 90deg turn from full open to full closed are classified as this

Back 135

1/4 turn valves

Front 136

What is the rough classification of small valves

Back 136

2" NPS or smaller

Front 137

what is galling

Back 137

a tearing of the surface that occurs when two pieces of metal slide across each other under high contact stresses