Valves

Question 1

What are the applications for valves?

Answer 1

Starting and stopping flow
Regulating or throttling flow
Preventing reverse flow
Regulating pressure
Relieving pressure
Isolating circuits or components

Question 2

What are the valve materials?

Answer 2

Bronze
Cast iron
Malleable iron
Steel
Stainless steel

Question 3

What materials are used for the valve packing?

Answer 3

Teflon
Teflon-impregnated asbestos
Graphite-impregnated asbestos
Semi-metalic packing
Metal wire re-enforced

Question 4

What markings must be present when selecting a valve?

Answer 4

Manufacturers name and trademark
Service ratings
Material type
CSA markings

Question 5

What does WOG mean on a valve?

Answer 5

Water, oil, Gas

Question 6

What does CWP Stand for?

Answer 6

Cold working pressure

Question 7

What does WSP on a valve mean?

Answer 7

Working steam pressure

Question 8

Where will you find flange connections most likely?

Answer 8

Larger valves

Question 9

Are welded fittings suitable for high temp and high pressure?

Answer 9

Yes

But should not be used where dismantle may be necessary

Question 10

Where are soldered connections used?

Answer 10

Low pressure low temperature

Question 11

What is the most common joint?

Answer 11

Threaded

Question 12

What are gate valves used for?

Answer 12

Full flow or no flow.

Do not use for throttling

Question 13

Where would you find plug valves?

Answer 13

Gas supply lines
Low pressure steam line
Water treatment
Pulp paper and chemical industries

Question 14

Ball valves were deigned for on/off valves. Can they be used to throttle?

Answer 14

Yes

Question 15

What are some benefits of butterfly valves?

Answer 15

Low pressure drop across fully opened valve
Easy to operate
Relativity light weight
Compact
Often used for throttling

Question 16

Where are needle valves used?

Answer 16

Where precise fluid flow needs to be achieved

Question 17

This valve is used for throttling and regulating flow but has much more resistance to flow then a gate valve?

Answer 17

Globe valve

Question 18

Angle valve is the same operating principle as a _______ valve?

Answer 18

Angle valve

Question 19

What is different about balance valves then globe valves?

Answer 19

Require much less force to operate

Question 20

When are diaphragm valves used?

Answer 20

For throttling corrosive and toxic materials

Question 21

When would you use a check valve?

Answer 21

When you don’t want the fluid to flow back words when pressure is off.

Question 22

What is the purpose of a over pressure relief valve?

Answer 22

To prevent equipment damage and protect workers

Question 23

What is a pressure safety valve for?

Answer 23

Provide rapid means of getting rid of excess pressure in piping . Use with compressible gases and steams