2ND 13

Question 1

A program designed to improve valve care and operating and maintenance procedures will promote:

a) plant reliability
b) plant safety
c) plant efficiency
d) all three

Answer 1

d) all three

Question 2

The metal offering the greatest resistance to cavitation is:

a) stainless steel
b) brass
c) bronze
d) monel

Answer 2

a) stainless steel

Question 3

Chromium and nickel are both added to steel to improve its ability to:

a) withstand high temperatures
b) withstand heavy shock
c) resist acid corrosion and cavitation
d) accept pressure variations

Answer 3

c) resist acid corrosion and cavitation

Question 4

Resistance to flow through a valve can be caused by:

a) metal roughness
b) protuberances inside the valve
c) change in the direction of flow
d) all three

Answer 4

d) all three

Question 5

Which of the below fittings would not normally be used with a gate valve:

a) by-pass line
b) outside lever and weight
c) clean-out plate
d) non-rising stem

Answer 5

b) outside lever and weight

Question 6

A quick-opening valve should be closed slowly to:

a) prevent wear on the stem threads
b) protect the packing from blowing out
c) prevent hydraulic shock caused by water hammer
d) prevent erosion of the seat

Answer 6

c) prevent hydraulic shock caused by water hammer

Question 7

All of the below valves may be float operated except:

a) Clayton valve
b) air-inlet valves
c) air-outlet valves
d) blowoff valves

Answer 7

d) blowoff valves

Question 8

Which of the below valves would normally be used to regulate fluid volume in a hydroelectric plant?

a) needle valves
b) butterfly valves
c) gate valves
d) roto valves

Answer 8

a) needle valves

Question 9

What type of gate valve most likely be used to reduce as much as possible the erosive action of water flowing at high velocity through high pressure gates?

a) Taintor
b) sliding
c) Stoney
d) Paradox

Answer 9

d) Paradox

Question 10

All of the below valves are normally used for crest control except:

a) radial gates
b) cylinder gates
c) sliding gates
d) paradox gates

Answer 10

d) paradox gates

Question 11

Valves are rated by the…………… and temperature they are designed to handle.

a) size
b) pressure
c) material
d) fluid

Answer 11

b) pressure

Question 12

The highest working pressure rating used for valves is?

a) water
b) oil
c) gas
d) steam

Answer 12

d) steam

Question 13

Pressure drop can be defined as a………….. in energy or a…………… in pressure, in a pipeline, due to the resistance in it.

a) gain - loss
b) loss – reduction
c) gain – gain
d) increase - loss

Answer 13

b) loss – reduction

Question 14

What type of connections would you use on a large valve?

a) threaded
b) welded
c) flanged
d) soldered

Answer 14

c) flanged

Question 15

A_______ valve has a “s” shape path and is used for______ flow.

a) plug - regulating
b) globe – throttling
c) ball – checking
d) butterfly - full

Answer 15

b) globe – throttling

Question 16

Stem packing is used to prevent fluid from leaking between the valve_________ and valve body.

a) stem
b) inlet
c) seat
d) outlet

Answer 16

a) stem

Question 17

Which valve does not require packing?

a) globe valve
b) gate valve
c) diaphragm valve
d) butterfly valve

Answer 17

c) diaphragm valve

Question 18

Air vent valves include:

a) ball float valves, vacuum breakers, balanced valve, safety and relief valves
b) ball float valves, vacuum breakers, coffin valve, safety and relief valves
c) ball float valves, vacuum breakers, coffin valve, safety and pressure reducing valves
d) blow off valves, vacuum breakers, coffin valve, safety and relief valves

Answer 18

b) ball float valves, vacuum breakers, coffin valve, safety and relief valves

Question 19

Piston operated valves require________ pressure to operate.

a) pneumatic
b) spring
c) gas
d) hydraulic

Answer 19

d) hydraulic

Question 20

Needle valves are used for?

a) regulating flow
b) a shut off valve
c) impulse wheels
d) all of the above

Answer 20

d) all of the above