164 Valves Questions and Answers

Explore 164+ Valves questions and answers covering valve types, valve operation, control valves, actuators, valve sizing, maintenance, troubleshooting, and industrial process control applications.

This collection includes technical questions related to:

Control Valves
Globe Valves
Ball Valves
Gate Valves
Butterfly Valves
Check Valves
Pressure Relief Valves
Safety Valves
Valve Actuators
Pneumatic Valves
Electric Actuators
Valve Positioners
Valve Sizing
Valve Maintenance

The questions cover valve construction, operating principles, flow control, valve characteristics, actuator systems, positioners, troubleshooting techniques, maintenance practices, valve selection, and practical applications commonly used in process industries.

These Valve questions are useful for instrumentation engineers, process engineers, maintenance technicians, control valve specialists, engineering students, and industrial professionals seeking to improve their knowledge of industrial valve technologies.

Browse the Valve questions below and strengthen your understanding of control valves, isolation valves, safety valves, and industrial flow control systems.

164 Valves Questions

S.No.	Valves Question
1	After an adjustment of the packing gland on a valve that had a minor packing leak, an operator attempts to operate the valve, but finds the valve is stuck ___
2	Why are gate valves generally not used to throttle water flow ___
3	In a comparison between globe valves and gate valves in the same water system application, globe valves ___
4	In a comparison between a globe valve and a gate valve in the same water system application, the gate valve has a ___ pressure drop when fully open and is the ___ choice for throttling
5	Consider a 3-inch gate valve and a 3-inch globe valve in the same flowing water system application ___
6	In a comparison between a typical gate valve and a typical globe valve in the same water system application with both valves fully open, the gate valve has a ___ pressure drop and is normally used in ___ flow applications
7	Consider a 3-inch gate valve and a 3-inch globe valve in separate but identical operating water systems ___
8	Which one of the following is a disadvantage associated with using a gate valve, versus a globe valve, to throttle flow in a cooling water system ___
9	After an adjustment of the packing gland on a valve that had a minor packing leak, the operator attempts to operate the valve, but finds that the valve is stuck ___
10	In a comparison between gate valves and globe valves in the same water system application, gate valves ___
11	A gate valve is generally a poor choice for throttling fluid flow because ___
12	Gate valves should not be used to throttle fluid flow because ___
13	Gate valves are most often used to ___
14	Globe valves are preferred over gate valves for throttling because ___
15	Some valve positioning (drive) devices are capable of stopping the valve between a fully open and a fully closed (throttled) position ___
16	Which one of the following valves is most likely to be used in a throttling application ___
17	In a comparison between ball valves and butterfly valves in the same cooling water system application, the valve that would typically experience the greater seat leakage when fully closed with a large differential pressure is the ___ valve
18	In a comparison between ball valves and butterfly valves in the same water system application, the valve that would typically be more leak-tight when fully closed with a high differential pressure is the ___ valve
19	In a comparison between ball valves and butterfly valves in the same water system application, the valve that typically would allow more leakage when fully closed with a high differential pressure is the ___ valve
20	In a comparison between butterfly valves and ball valves, ___ valves are generally more leak- tight in high pressure applications; and ___ valves generally exhibit the smaller pressure decrease when fully open
21	Refer to the drawing of a valve ___
22	An operator attempts to close a fully-open upright manual gate valve to isolate a pump in a cooling water system that has been cooled down for maintenance ___
23	Which one of the following describes the function and use of the backseat on a manual valve ___
24	A typical check valve is designed to ___
25	Which one of the following is the type of valve used to control the direction of fluid flow through a system and prevent backflow ___
26	A stop check valve is a type of check valve that ___
27	Check valves are normally used to prevent ___
28	When the valve was remotely opened and closed to verify operability, the measured valve stroke time in each direction was 15 seconds, which is shorter than normal for this valve ___
29	A typical motor-operated valve has been returned to service following a complete maintenance overhaul of the valve and actuator ___
30	Which one of the following types of similarly sized valves requires the most manual valve stem rotation to move the valve from fully open to fully closed ___
31	A typical motor-operated valve (MOV) has just been opened from the main control room, and the breaker for the MOV has been opened ___
32	When manually closing a motor-operated valve, why must the operator avoid using excessive valve seating force ___
33	A surveillance test procedure is being performed on a typical motor-operated valve (MOV) with a declutch lever that is used in an emergency core cooling system (ECCS) application ___
34	A typical motor-operated valve with a declutch lever is installed in an emergency core cooling system (ECCS) application ___
35	When the manual declutch lever of a motor-operated valve is moved out of the normal position, it ___ the motor and ___ the handwheel
36	When manually positioning a motor-operated valve, why must care be taken to avoid using excessive valve seating/backseating force ___
37	Two common types of check valves used in nuclear power plants are ___
38	Prior to shifting a valve controller from automatic to manual control, why should the automatic and manual controller output signals be matched ___
39	When transferring a valve controller from the manual mode to the automatic mode, the automatic valve controller output signal should be ___ the manual valve controller output signal at the time of transfer
40	Refer to the drawing of a water supply pump with two suction sources. All motor-operated valves (MOVs) are currently closed ___
41	An adjustment has just been completed on the packing gland of a motor-operated gate valve to stop a minor stem leak ___
42	During a local inspection of a manually operated 12-inch gate valve, the valve stem is observed to extend outward from the valve handwheel by 1 inch ___
43	Which one of the following is a generally accepted method for locally verifying that a manual valve is fully closed in a depressurized piping system ___
44	To verify a manual valve in an operating system is closed, the operator should observe valve position indication and operate the valve handwheel in the ___
45	Which one of the following is a generally accepted method for locally verifying that a manual valve is fully closed in a depressurized static piping system ___
46	To verify the position of a fully open manual valve in an operating system, the operator should operate the valve handwheel ___
47	To verify that a manual valve in a pressurized water system is closed, the operator should observe valve position indication and operate the valve handwheel in the ___
48	Which one of the following is not a generally accepted method for locally verifying that a valve is open ___
49	The valve actuator may be shown with or without applied air pressure ___
50	Which valves are currently shown in their failed (i.e., no air pressure applied to the actuator) positions ___
51	Refer to the drawing of four air-operated valves ___
52	Refer to the drawing of a pneumatically-operated valve. The valve actuator may be shown with or without air pressure applied to it
53	Refer to the drawing of a spring-loaded air-operated valve. Upon a loss of air pressure, this valve will ___
54	Refer to the drawing of a spring-loaded air-operated valve in which the solenoid is shown energized ___
55	The figure currently depicts normal air supply pressure and an energized solenoid. What will be the valve position following a loss of electrical power to the solenoid ___
56	Refer to the drawing of a spring-loaded air-operated valve shown in a throttled position ___
57	How will a typical motor-operated valve respond to a loss of electrical power to the valve actuator ___
58	Refer to the drawing of a hydraulically-operated valve that is shown in a throttled position ___
59	Refer to the drawing of an open system with subcooled water flowing through valves A, B, C and D ___
60	Which one of the following could be responsible for the difference between the initial and current steady-state conditions for the throttle valve ___
61	Subcooled water is flowing through a throttle valve in an open system ___
62	The valve that typically requires the least linear travel of the disk from fully closed to fully open is the ___ valve; and the valve that produces the greatest pressure drop when fully open is the ___ valve
63	Refer to the drawing of an operating cooling water system (see figure below) in which valves A and B are identical ___
64	Which one of the following could be responsible for the difference between the initial and current steady-state conditions for the throttled valve ___
65	Subcooled water is flowing through a throttle valve in an open system. The initial steady-state conditions for the throttle valve are as follows ___
66	Subcooled water was flowing through a throttled valve with the following initial parameters ___
67	Consider a 6-inch globe valve and a 6-inch gate valve in the same water system application ___
68	Refer to the centrifugal pump operating curve with two system head loss curves ___
69	Which one of the following types of similarly sized valves in an operating water system produces the least frictional head loss when fully open ___
70	Refer to the drawing of a cooling water system in which both centrifugal pumps A and B are operating ___
71	Which one of the following statements describes the throttling characteristics of a typical globe valve ___
72	Which one of the following statements describes the flow rate characteristics of a typical globe valve in an operating water system ___
73	A control valve is most likely to experience cavitation when the valve is almost fully ___ because of a relatively ___ pressure drop across the valve seat
74	Consider a typical gate valve and a typical globe valve in the same water system application ___
75	Which one of the following statements describes the flow rate characteristics of a typical gate valve in an operating water system ___
76	If a pressure control valve at the outlet of a heat exchanger opens farther, system flow rate will ___; and system head loss will ___
77	The tank is protected by two relief valves that discharge to the atmosphere. The relief valves have the following characteristics ___
78	A cooling water system uses a conventional relief valve (not pilot-operated) with a bench-tested setpoint of 60 psig ___
79	A completely full water storage tank is being hydrostatically tested to 300 psig using a positive displacement pump (PDP) with a smooth and constant discharge flow rate of 4 gpm ___
80	A completely full water storage tank is being hydrostatically tested to 200 psig using a positive displacement pump (PDP) with a smooth and constant discharge flow rate of 4 gpm ___
81	A completely full water tank is being hydrostatically tested to 180 psig using a positive displacement pump (PDP) with a smooth and constant discharge flow rate of 6 gpm ___
82	A completely full water storage tank is being hydrostatically tested to 200 psig using a positive displacement pump (PDP) with a smooth and constant discharge flow rate of 6 gpm ___
83	Vessels A and B are identical except that vessel A receives overpressure protection from an installed safety valve ___
84	Water storage tanks A and B are identical except that tank A receives overpressure protection from a relief valve, whereas tank B uses a safety valve ___
85	Which one of the following is a difference between a typical relief valve and a typical safety valve ___
86	Refer to the drawing of two identical pressure vessels with identical relief valve protection. Both vessels have been pressurized to 50 psig and then isolated ___
87	The difference between the setpoint pressure at which a safety valve opens and the pressure at which it closes is called ___
88	The difference between the setpoint pressure at which a relief valve begins to open and the pressure at which it is fully open is called ___
89	Refer to the drawing of two identical pressure vessels with identical relief valve protection ___
90	The tank is protected by a relief valve and a safety valve that both discharge to the atmosphere. The valves have the following characteristics ___
91	A main steam system uses a combination of safety and relief valves for overpressure protection ___
92	The tank is protected by a relief valve and a safety valve that both discharge to the atmosphere ___
93	Refer to the drawing of two identical water storage tanks ___
94	A completely full water storage tank is being hydrostatically tested to 200 psig using a positive displacement pump (PDP) with a smooth and constant discharge flow rate of 8 gpm ___
95	Given the following pressure specifications for a safety relief valve (SRV) ___
96	A completely full water storage tank is being hydrostatically tested to 100 psig using a positive displacement pump (PDP) with a smooth and constant discharge flow rate of 10 gpm ___
97	Given the following specifications for a main steam safety valve (MSSV) ___
98	A vertical safety valve with a 2-inch diameter disk has a compressed spring applying 2,400 lbf to the top of the valve disk in opposition to system pressure ____
99	A vertical safety valve has a compressed spring assembly that is applying 2,500 lbf to the top of the valve disk in opposition to system pressure ___
100	Refer to the drawing of a typical safety valve. The component indicated by the solid arrow is used when necessary to manually ___
101	A vertical safety valve with a 3-inch diameter disk has a spring applying 1,000 lbf to the top of the valve disk in opposition to system pressure ___
102	A vertical safety valve has a compressed spring assembly that is applying 1,200 lbf to the top of the valve disk in opposition to system pressure ___
103	Which one of the following statements describes the operation of a reactor pressure vessel safety valve ___
104	Which one of the following valves provides overpressure protection to limit the internal pressure in vessels, and thus protect personnel and equipment ___
105	Which one of the following describes the operation of a safety valve installed on a high pressure steam system ___
106	Which of the following actuating control valves is electromagnetically operated?
107	Which of the following statements about pressure relief valves is false?
108	In valve selection an examination of the fluid to be handled is made to determine its ____ and ____
109	Valve sizes are selected in accordance with the ___ needed and permissible fluid-friction ____
110	Identify List factors involved in valve selection
111	Variables affecting material selection are ___
112	______ valve bodies in general can be used on water service up to temperatures of about 250Â°C
113	The conventional disc globe valve is fairly ___ and popular in low-pressure service where severe ___ is not required
114	The plug type globe valve is the best of the three types for ______ and ______ service
115	High-pressure single-ported globe bodies, or plug type, are often used in production of _____ and ____
116	The eccentric plug valve, is specially designed for _____
117	The mixing valve is designed with two _____ and one _____ for blending two fluids
118	In a direct operating, electric actuator ___
119	Diaphragm valves have three basic parts ___
120	A T-Ported component can be found in some ________ Valves
121	Solenoid Valves are used in ___
122	Diaphragms are made of materials resistant to the particular fluids being transported
123	The purpose of the bolted on jacket on some plug valves is to ___
124	Which best describes a spring-loaded diaphragm actuator
125	The maximum temperature of fluids handled by a diaphragm valve must be below the temperature limit for the ___
126	Plug valve gland types include ___
127	A lined butterfly valve could be described as ___
128	Globe valves have the largest pressure drop or head loss of the valve types
129	In gate valves, the parts most severely worn are the discs and seats
130	What is the purpose of the bolted jacket’s?
131	The diverting valve is a three-way valve, with _____ inlet and _____ outlets
132	Identify Diaphragm Valve applications
133	The butterfly valve is often used as a final control element in ____ or large ______ piping systems
134	Identify the two ways butterfly valves are installed into a piping system
135	Identify the three subcategories of butterfly valves
136	Identify advantages of diaphragm valves
137	The purpose of a pressure reducing valve is to ___
138	A boiler feedwater stop valve ___
139	An outside screw and yoke valve ___
140	A globe valve should be used in the feedwater line
141	One purpose of the small valve on top of the shell or the water column on most boilers is to ___
142	What is the flow rate in m3/h when the valve opens to 45%?
143	What is the flow rate in m3/h when the valve opens to 30%?
144	QUiz on quick opening and equal percentage valves
145	For water, if the pressure drop across the valve is 15 ft of water, CV = 60, what is the flow rate? The valve is fully open
146	[Valves] Match the following ___
147	A control valve has to control the inlet flow of cooling water to a cooling jacket on an exothermic chemical reactor. We should select
148	Quiz on Single seated valve and double seated valve
149	What is the main purpose of the control valve positioner?
150	A valve which often contains a dashpot to cushion the action of the valve is the ___
151	The material designation of a valve ___
152	[Quiz] All markings on valves shall be ___
153	[Quiz] A globe valve ___
154	A valve which requires specific and routine lubrication is the ___
155	In order to extend the life of valve packing we can ___
156	Service designation of a valve indicates the ___
157	A valve which has the best capability of handling slurries and fluids with high suspended solids is ___
158	The maximum temperature, which a non-special alloy steel valve can be used for ___
159	The by-pass around a regulating valve should contain a ___
160	A check valve is a valve that ___
161	In order to ensure safe and continuous operation of a pressure reducing valve, the valve station should have ___
162	Regular inspection of a valve is important and items which require close scrutiny are the ___
163	The advantage of a rising spindle steam stop valve is that ____
164	About the Valves MCQ category