Introduction to Valves

Question 1

A valve which has the best capability of handling slurries
and fluids with high suspended solids is the
a) globe valve
b) gate valve
c) ball valve
d) needle valve
e) plug valve

Answer 1

c) ball valve

Question 2

A valve having minimum wire drawing and seat erosion is the

a) globe valve
b) gate valve
c) plug valve
d) hand valve
e) wedge gate valve

Answer 2

a) globe valve

Question 3

A valve which requires specific and routine lubrication is
the
a) butterfly valve
b) globe valve
c) pressure reducing valve
d) check valve
e) tapered plug valve

Answer 3

e) tapered plug valve

Question 4

A valve which often contains a dashpot to cushion the action
of the valve is the
a) needle valve
b) swing check valve
c) pressure regulating valve
d) lift check valve
e) safety valve

Answer 4

d) lift check valve

Question 5

Increasing the spring tension of a pressure regulating valve
will
a) increase the regulated pressure downstream of the valve
b) close the valve tight
c) decrease the regulated pressure downstream of the valve
d) cause the valve to go to the wide open position
e) reduce or minimize the cycling or “hunting” of the valve

Answer 5

a) increase the regulated pressure downstream of the valve

Question 6

In order to ensure safe and continuous operation of a
pressure reducing valve, the valve station should have
a) a safety valve on the downstream side
b) a by-pass loop, downstream safety valve, and a downstream
pressure gage
c) the piping to the station made of at least Schedule 80
piping
d) a Y-strainer immediately after the valve
e) a metal rather than composition diaphragm

Answer 6

b) a by-pass loop, downstream safety valve, and a downstream

pressure gage

Question 7

A check valve is a valve that

a) allows flow in one direction only
b) allows flow in two directions
c) allows flow at regular intervals
d) does not allow any flow at all
e) has a locking spindle

Answer 7

a) allows flow in one direction only

Question 8

The by-pass around a regulating valve should contain a

a) rising stem gate valve
b) non-rising stem gate valve
c) swing check valve
d) rising stem globe valve
e) lift type check valve

Answer 8

d) rising stem globe valve

Question 9

A gate valve:

1. has less restriction in a line than a globe valve
2. should be operated either fully open or fully closed
3. is used to throttle flow
4. is used for different applications than a globe valve
   a) 1, 2, 3, 4
   b) 1, 3, 4
   c) 1, 2, 4
   d) 2, 3, 4
   e) 2, 4

Answer 9

c) 1, 2, 4

Question 10

A globe valve:

1. has less restriction in a line than a gate valve
2. should be operated either fully open or fully closed
3. is used to throttle flow
4. is used for different applications than a gate valve
   a) 1, 2, 3, 4
   b) 2, 3, 4
   c) 1, 2, 4
   d) 1, 3, 4
   e) 2, 4

Answer 10

d) 1, 3, 4

Question 11

Butterfly valves have several advantages such as they:
1. only require 1/4 turn to open
2. are self-cleaning
3. provide negligible pressure drop when fully open
4. can have the disc lubricated while in operation
5. are self-adjusting so alignment is not required during
installation
a) 1, 3
b) 2, 3
c) 2, 4
d) 3, 4, 5
e) 1, 2, 5

Answer 11

b) 2, 3

Question 12

The maximum temperature which a non-special alloy steel valve
can be used for is
a) 280 degrees C
b) 425 degrees C
c) 650 degrees C
d) 1,000 degrees C
e) 1,500 degrees C

Answer 12

c) 650 degrees C

Question 13

Relative to valves, a frequent cause of serious accidents is
due to
a) valves being of the wrong size
b) a lack of valve maintenance
c) inadequate operational training
d) manufacturing defects
e) wrong materials of construction

Answer 13

e) wrong materials of construction

Question 14

In order to extend the life of valve packing we can

a) operate the valve at lower temperatures
b) lubricate the packing regularly with oil
c) replace the packing annually
d) manipulate the valve slower
e) manipulate the valve on a regular basis

Answer 14

b) lubricate the packing regularly with oil

Question 15

Regular inspection of a valve is important and items which
require close scrutiny are the
a) disc and seat
b) stem and body
c) seat and stem
d) stuffing box and spindle threads
e) hand wheel and packing

Answer 15

a) disc and seat

Question 16

Valve packing, depending on service, may be made from:

1. Teflon
2. manila
3. impregnated asbestos
4. Halon
5. semi-metallic material
   a) 1, 2, 5
   b) 2, 3, 4
   c) 1, 2, 3
   d) 3, 4, 5
   e) 1, 3, 5

Answer 16

e) 1, 3, 5

Question 17

“Valve trim” consists of the following parts:

1. stuffing box
2. disc
3. seat ring
4. bonnet
5. valve stem
6. body
7. guide bushings
   a) 1, 2, 4, 6
   b) 3, 4, 5, 6
   c) 2, 3, 5, 7
   d) 1, 2, 6, 7
   e) 2, 3, 4, 5

Answer 17

c) 2, 3, 5, 7

Question 18

Material designation of a pipe fitting
a) gives where the material is used
b) tells what material makes up the fitting
c) gives the temperature to which the fitting can be
subjected
d) tells what the material is suited for
e) is not required for low pressure steam service

Answer 18

b) tells what material makes up the fitting

Question 19

All markings on pipe and pipe fittings shall be

a) painted with black paint
b) made with capital letters
c) covered for protection
d) legible
e) written vertically in capital letters

Answer 19

d) legible

Question 20

Service designation of a pipe fitting indicates the

a) type of liquid used in the fitting
b) type of gas used in the fitting
c) temperature-pressure rating of the fitting
d) maximum pipe fluid flow velocity
e) maximum viscosity of the fluid

Answer 20

c) temperature-pressure rating of the fitting

Question 21

Pressure and/or temperature rating of a fitting is known as

a) material designation
b) manufacturer’s trademark
c) service designation
d) thermal designation
e) work requirement

Answer 21

c) service designation

Question 22

The advantage of a rising spindle steam stop valve is that:
1. you can tell from a distance if the valve is open or
closed
2. it provides a place to install isolation tags
3. it may be easily lubricated
4. the threaded part is not exposed to corrosion by the
high temperature steam
a) 3, 4
b) 1, 2, 4
c) 1, 2, 3
d) 2, 3, 4
e) 1, 3, 4

Answer 22

e) 1, 3, 4

Question 23

The purpose of the non-return valve is to

a) prevent water from entering the steam header
b) prevent the back flow of steam
c) drain condensate from the main steam header
d) prevent the safety valve from popping
e) regulate the flow of steam from the boiler

Answer 23

b) prevent the back flow of steam