Test 3 Flashcards
(186 cards)
1
Q
- T/F Both relief valves and safety valves are the two most common safety devices designed to prevent overpressure conditions in process industries.
A
True
2
Q
________ is the abnormal rapid reciprocating motion of the movable parts of a relief valve in which the disc contacts the seat repeatably.
A
Chatter
3
Q
______ is the pressure increase over the Maximum Allowable Working Pressure (MAWP) of equipment during discharge through the protecting pressure relief valve and is usually expressed as a percentage of the MAWP.
A
Accumulation
4
Q
_______ is the pressure at which the relief valve starts to open.
A
Set Pressure
5
Q
The sun is a pressure source for relief valves in thermal expansion relief valve scenarios.
A
True
6
Q
T/F A relief valve will rapidly fully open (pop) when the set pressure is reached.
A
False
7
Q
T/F The pilot-operated valve allows for more accurate control over the set pressure compared to a spring-operated relief valve.
A
True
8
Q
A pilot-operated relief valve is ____ susceptible to chattering compared to a spring-operated relief valve.
A
less
9
Q
A spring operated relief valve ______ require an external power source.
A
does not
10
Q
Label the parts of the spring operated relief valve. A
A
Bonnet
11
Q
Label the parts of the spring operated relief valve.
B
A
Spring
12
Q
Label the parts of the spring operated relief valve. C
A
Disc
13
Q
Label the parts of the spring operated relief valve. D
A
Adjusting Ring
14
Q
Label the parts of the spring operated relief valve. E
A
Nozzle
15
Q
Label the parts of the spring operated relief valve. F
A
Body
16
Q
T/F In systems containing flammable fluids, the diverted fluid is usually routed through a piping system to a flare header or relief header.
A
True
17
Q
This type of relief valve is designed to open when the temperature of the process fluid exceeds a certain temperature limit.
A
Temperature-Activated Relief Valve
18
Q
Identify the bellows in the balanced bellow relief valve A
A
Guide
19
Q
Identify the bellows in the balanced bellow relief valve B
A
Metal Bellows
20
Q
Identify the bellows in the balanced bellow relief valve C
A
Disc Holder
21
Q
If you require a relief valve that is used in a process where the fluid is dirty and contains particulate, you should use a ______ pressure relief valve.
A
Nozzle Type
22
Q
With a pressure safety valve (PSV), when the set pressure is reached the PSV will ________.
A
Open Rapidly to full open
23
Q
Name an application where a pressure safety valve is used.
A
Steam Boilers
24
Q
Section VIII of the ASME Code covering pressure vessels requires pressure relief valves to have lifting levers on __________________________________
A
air, Steam and hot water (over 140°F) service
25
What are the two common sizes for thermal relief valves.
1” x 1” or 3/4” x 1” having minimum orifice area of 0.110 in squared.
26
A tank that has sun exposure has inlet and outlet valves that are often closed. The tank holds a liquid that expands when heated. Should the tank have a thermal relief valve?
Yes
27
Relief valves are sized based on the _______ area.
orifice
28
The API standard for relief valve orifice sizes are designated by _____.
letter
29
Which API orifice size has a bore dimension of 0.785 in2?
H
30
For a 4” x 6” relief valve, the outlet connection size is _____ inch.
6
31
A hard seat relief valve uses a _______ to ______ seat valve.
metal to metal
32
Name an application that a hard seat relief valve will be used in.
Extremely high temperature applications
33
T/F The composition of the sealing material in the internals of the relief valve will depend upon on the compatibility of media flowing through the valve.
True
34
T/F Pressure relief valves and safety valves should be mounted in the vertical position (upright with the spindle vertical).
True
35
T/F It is good practice to make the inlet piping a smaller diameter than the relief valve inlet size.
False
36
T/F For flanged relief valves, it is a good practice to tighten one side all the way down before tightening the other side
False
37
The nominal size of the outlet piping __________.
must be as large or larger diameter than the relief valve out size
38
T/F The outlet piping of a relief valve should always be supported to prevent damage to the relief valve.
True
39
Name the two common end connections for relief valves.
Threaded and flanged
40
Name two industries that use relief valves.
Chemical processing & Oil and Gas Industry
41
The symbol shown is a symbol is for a ______.
P&ID symbol for a relief valve
42
The symbol shown is a symbol is for a ______.
Pilot operated relief valve
43
T/F Rupture discs can be used multiple times.
False
44
What are the two most used pressure protection devices in industrial plants?
Rupture discs and pressure safety valves
45
T/F Rupture discs provide an instant response to over or under pressurization in a piping system.
True
46
T/F Relief valves and safety valves can fail to function against overpressure.
True
47
T/F Rupture discs can be used in combination with a pressure safety or relief valve.
True
48
T/F Rupture disc can be either round or square.
True
49
_______ acting rupture discs allow higher working pressures and tighter tolerances.
Reverse
50
Identify the domed rupture disc
Forward Acting
51
Identify the domed rupture disc
Reverse Acting
52
Name two materials that rupture discs are constructed from.
Carbon Steel and Stainless Steel
53
Name three industries where rupture discs are used.
Petrochemical, railroad and Chemical
54
Name the two ways in which rupture discs are installed.
Directly between flanges or inserted into a corresponding rupture disc holder which is then mounted between flanges
55
Name an application where a rupture disc is used in a primary relief option.
A pressure vessel with no permanent supply connection
56
Name an application where a rupture disc is used in a primary relief option. Can be used with pressure relief valves in parallel.
Rapid & large pressure rise where extremely fast action is required to prevent catastrophic failure.
57
Name a benefit of using a rupture disc upstream of a relief valve.
Protects the PSV/PRV from fluids containing solids, that may plug/damage the valves.
58
The burst pressure requested by the user is the ________ burst pressure.
specified
59
The accuracy of the rupture disc’s performance is known as burst _______.
tolerence
60
Name two advantages of a rupture disc.
Leak tight seal and High reliability
61
Name a disadvantages of a rupture disc.
Must be replaced after each occurrence
62
The P&ID symbol for a rupture disc is
b
63
T/F A check valve allows fluid (liquid or gas) to flow through it in only one direction.
True
64
What is the primary function of a check valve?
Protect mechanical equipment in a piping system by preventing reversal of flow by the fluid.
65
How are check valves labeled to show the proper direction of flow?
Typically have an arrow on its body to show the proper direction of the flow
66
What is cracking pressure?
The minimum upstream pressure required to open a check valve enough to allow detectable flow.
67
The most common check valve used in industry is the _______ check valve.
Swing
68
This type of check valve is designed to fit in tight spaces and is a good choice where a short length check valve is required.
Wafer check valve
69
T/F It is possible for foreign particles to get stuck between the check valve seat and disc.
True
70
Label the components of the wafer check a.
Plate
71
Label the components of the wafer check valve b.
Body
72
Label the components of the wafer check valve c.
Spring
73
Label the components of the wafer check valve d.
Plate Hinge Spring
74
Label the components of the wafer check valve e.
Spring Restraining Pin
75
Name three commonly used check valves.
Swing, wafer and ball
76
Wafer check valves can be installed in _____ positions.
both horizontal and vertical
77
T/F For systems with pulsating flow, a swing check valve is a good choice.
False
78
_______ are used in wafer check valves to assist the valve in closing and preventing reverse fluid flow.
Springs
79
Name two recommended guidelines for inspection of swing check valves.
Check for leakages and look for any sign of corrosion, rust and wear
80
T/F Swing check valves are prone to water hammer issues.
True
81
T/F A wafer check valve can be inspected while in service.
False
82
The only moving part of a ball check is a(n) ___________.
Spherical ball
83
T/F For a ball check valve, the ball is available in different weights to match the application.
True
84
Label the parts of the piston check valve a.
Springs
85
Label the parts of the piston check valve b.
Spacers
86
Label the parts of the piston check valve c.
Seating Surfaces
87
Label the parts of the piston check valve d.
Seating Surfaces
88
Label the parts of the piston check valve e.
Valve Stem
89
Label the parts of the piston check valve f.
Valve Bonnet
90
Label the parts of the piston check valve g.
Cage
91
Label the parts of the piston check valve h.
Main Plug Valve
92
This part of the piston check valve is used to help in closing the valve immediately when suction pressure starts reducing.
The Spring
93
This type of check valve has a short linear stroke and spring return action combine to close the valve prior to flow reversal which effectively eliminates the shock and water hammer.
Silent Check Valves
94
What is the likely cause of a chattering or vibrating silent check valve.
Fluid moving at a high velocity
95
The P&ID symbol for a check valve is ______.
b
96
What is a sampling valve used for?
For taking a representative portion of a fluid (gases, liquids, solids, or slurries) from a live process to test typically for the purpose of identification, quality control, or regulatory assessment. Also can be used of or injecting a substance into a process.
97
Name the three common sampling valve end connections.
Flanged, Welded and Threaded
98
T/F In the chemical industry, a sample must not contain remains of previous batches that may have stayed in the valve’s dead space.
True
99
What is the problem with using a ball valve for obtaining a representative sample?
Liquid stays in the ball and the next time it is opened, the liquid flows first. The valve must be flushed before the sample is taken.
100
T/F When sampling hazardous chemicals, it is important that the operator is not exposed to toxic fumes or vapors.
True
101
What is the advantage of using a sampling valve with a piston?
The valve ensures that new product samples are always taken with no prior sample material remaining.
102
In the natural gas industry to take a representative sample, the sampling probe should _____.
extended to the center third of the pipe
103
Name two components that are commonly added to a sampling probe in the natural gas industry.
Pressure regulator and membrane filter
104
What issue can liquid pose when included in the gas sample?
Impact the accuracy of the compositional analysis and damage the analyzer.
105
What does the A+ manifold have to monitor the pressure?
Pressure gauge and ball valve
106
Define an actuator.
An actuator is a device that converts energy into a mechanical force to enable movement of a valve.
107
Name three sources of energy for an actuator.
pneumatic (compressed air), pressure, hydraulic (oil) pressure or electric current which moves the internal mechanical parts of the actuator.
108
Provide the six basic functions that a valve actuator performs.
Move the closure component position, maintain the closure component position, seat the valve with sufficient torque, have a failure mode, provide proper rotational capabilities, Operate the appropriate speed.
109
In a single-acting actuator, what provides the power to return an actuator to its original position?
A spring provides the power to return the actuator to its original position.
110
T/F A double-acting actuator has ports on both sides of the piston.
True
111
What is the largest issue with electrical actuators?
They can overheat if there are extreme changes in duty cycle.
112
The amount of torque generated by a hydraulic actuator is ____.
High
113
What industry typically uses gas-over-oil actuators?
Natural Gas Industry
114
Name two types of valves that rotary actuators are used with.
Gate and Globe
115
Name the two main styles of linear actuators.
Diaphragm and piston (cylinder)
116
In direct-acting actuators, air enters the _____ area of the diaphragm.
Top
117
Direct-acting actuators are suitable for _______ applications.
Fail Open
118
Diaphragm actuators are typically used in _______ applications.
Throttling
119
Name two industries that use diaphragm actuators.
Power, oil & gas, process.
120
Indirect-acting actuators are suitable for _______ applications.
Fail Closed
121
Name the two supply pressure ranges for diaphragm actuators.
3 to 15 psi or 6 to 30 psi
122
Label the parts of direct acting diaphragm actuator 1.
Loading Pressure Connection
123
Label the parts of direct acting diaphragm actuator 2.
Diaphragm Case
124
Label the parts of direct acting diaphragm actuator 3.
Diaphragm
125
Label the parts of direct acting diaphragm actuator 4.
Diaphragm Plate
126
Label the parts of direct acting diaphragm actuator 5.
Actuator Spring
127
Label the parts of direct acting diaphragm actuator 6.
Actuator Stem
128
Label the parts of direct acting diaphragm actuator 7.
Spring Seat
129
Label the parts of direct acting diaphragm actuator 8.
Spring Adjuster
130
Label the parts of direct acting diaphragm actuator 9.
Stem Connector
131
Label the parts of direct acting diaphragm actuator 10.
Valve Stem
132
Label the parts of direct acting diaphragm actuator 11.
Yoke
133
Name two advantages of pneumatic diaphragm actuators.
Simplicity of operation and low maintenance
134
Name a disadvantage of a pneumatic diaphragm actuator.
Cost & maintenance of a compressed air system. Improperly maintained air system can provide air that is contaminated by oil or lubrication, leading to downtime and maintenance.
135
Piston actuators take supply pressure up to ____ psig
150
136
T/F Piston actuators are used when the thrust of a diaphragm actuator is too short to move the valve.
True
137
T/F Piston actuators can generate higher thrust due to the ability to take higher inlet supply pressures.
True
138
Label the parts of the piston actuator 1.
Loading Pressure Connection
139
Label the parts of the piston actuator 2.
Piston
140
Label the parts of the piston actuator 3.
Piston Seal
141
Label the parts of the piston actuator 4.
Cylinder Closure
142
Label the parts of the piston actuator 5.
Cylinder Closure Seal
143
Label the parts of the piston actuator 6.
Seal Bushing
144
Label the parts of the piston actuator 7.
Stem Connector
145
Name the type of actuator for the P&ID symbol
Electric or Motor
146
Name the type of actuator for the P&ID symbol
Diaphragm
147
Name the type of actuator for the P&ID symbol
Hydraulic
148
Name the type of actuator for the P&ID symbol
Piston
149
Name the type of actuator for the P&ID symbol
Electro/Hydraulic
150
Amount of torque to unseat an initially closed valve.
Breaking Torque
151
Amount of torque that leads to a valve being fully closed.
Closing Torque
152
Design to close a valve automatically in event of system failure.
Fail Closed
153
Design to open a valve automatically in event of system failure.
Fail Open
154
Design to have a valve stay in current position in the event of a system failure.
Fail Last Position
155
Air supply pressure required to operate a pneumatic actuator.
Supply Pressure
156
The material flowing through a valve.
Media
157
Throttling flow by varying the valve position between open & closed.
Modulating
158
Linear distance from the center of rotation upon which a force acts to produce torque.
Moment arm
159
Basic full open or full closed operation to start or stop flow.
On/Off Service
160
Force required to operate a valve expressed in foot-pounds
Operating Torque
161
Set of electrical contacts that are activated mechanically at a preselected position.
Limit Switch
162
Amount of force required to operate the control mechanism (valve)
Torque
163
The mechanism used to open and close a valve is known as ________.
actuator
164
The capability provided to actuators that allows the manual positioning of the actuator is known as a ___________.
Manual Override
165
The maximum amount of torque that can be implemented on a valve train before it malfunctions or is damaged is known as the __________.
MAST Maximum Allowable Stem Torque
166
The percentage of time a device is allowed to operate over a given period of time and is expressed in a percentage is known as _______.
Duty Cycle
167
A code established for electrical components by the National Electric Manufacturers Association is known as the _____ Rating.
NEMA
168
Identify the National Electric Manufacturers Association rating for the following electrical accessory enclosure applications - Indoor use and protects components from contact
NEMA 1
169
Identify the National Electric Manufacturers Association rating for the following electrical accessory enclosure applications -Indoor/outdoor use that is watertight and dust tight. Protects from windblown dust and rain.
NEMA 4
170
Identify the National Electric Manufacturers Association rating for the following electrical accessory enclosure applications - Indoor/outdoor use that is watertight and dust tight. Protects from windblown dust and rain and is corrosion resistant.
NEMA 4X
171
Identify the National Electric Manufacturers Association rating for the following electrical accessory enclosure applications-Explosion proof rating (Class I, Division 1, Groups A, B, C, and D) for an area that will contain gasoline or naptha.
NEMA 7
172
Identify the National Electric Manufacturers Association rating for the following electrical accessory enclosure applications - Explosion proof rating (Class II, Division 1, Groups E, F, G) for an area that will contain coal, coke dust, or flour.
NEMA 9
173
A machined coupling and plate, spool, or length of rectangular tubing designed to adapt an actuator to a valve is known as a __________.
Mounting Bracket
174
The maximum temperature of the flow media that is used in the selection of the proper valve material for the application is known as _______.
Maximum Service Temperature
175
The temperature of the air surrounding the actuator is known as the _________.
Ambient Temperature
176
This type of actuator uses compressed air or liquid to move the actuator in one direction and relies on a spring to return the actuator to its original position.
Single Acting
177
This type of actuator uses compressed air or liquid to both open and close the valve.
Double Acting
178
Name the two main types of actuators.
Rotary and Linear
179
T/F The most common manual operator on smaller quarter-turn valves is the basic lever.
True
180
On small valves where leverage is not needed, ____ shaped knobs are often used
these may be replaced by ovals, tees, or other
181
T/F Some manual levers have a means to lock them in place.
True
182
A lever with a _______ is also known as a dead man’s lever.
Spring Return
183
What purpose does the gearbox (gear assembly) serve with the hand wheel to operating the valve?
Increases mechanical leverage
184
Hand wheels with a gear assembly are commonly found on ball and butterfly valves larger than ___ inch
8
185
What accessory is added to access a large valve that is located out of reach from the ground?
Chain Wheel
186
A manual valve where the valve position needs to be known are equipped with a _______.
Position indicators
