Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

ChE Design > Valve selection > Flashcards

Valve selection Flashcards

1
Q

Shut-off valve or?

A

Block or isolation valve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Can be manual or automatic

A

Control valve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Example of shut off valve

A

Gate
Plug
Ball

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Gives positive seal in the close position and minimum resistance flow to flow when open

A

Shut off valve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

+available in the widest range of sizes and can be operated manually or by a motor
• have a straight-through flow channel and low
pressure drop when fully open

A

Gate valve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

best used when operated infrequently, as they
require several turns of the valve handle to close

Should not be opened partially as valve seals could be deformed

A

Gate / Slide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

• have the advantage that they only require a
quarter turn to open or close
• often actuated by solenoids and are used
where quick on-off switching is needed

A

Plug and Ball valve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Normally used flow control valve

A

Globe valve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Commonly used control valve

A

Diaphragm valve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Used for the control of gas and vapour flows

A

Butterfly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Usually globe valves with special trim designs

A

Automatic control valves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Good flow while keeping

A

Pressure drops low

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Valve must be sized to avoid:

A

Flashing out of hot liquid
Super critical flow of gases and vapours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

are used to
prevent back-flow of fluid in a process
line.
• They do not normally give an absolute
shut-off of the reverse flow.

A

Non-return valves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

depend
on gravity to close the valve, care
must be taken to orient the valve
properly when locating and installing it.

A

Swing- type check balvo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Two general types of pump

A

Dynamic
Positive displacement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Example of dynamic pump

A

Centri

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Examples of positive displacement

A

Reciprocating and diaphragm

19
Q

Most commonly used type in chem. Indus

A

Single-stage, horizontal, overhung centrifugal pump

20
Q

When small flow rates of additive must be added to a process, what will you use?

A

Positive displacement metering pumps

21
Q

Pp selection is made on? (2)

A

Flow rate
Head required

22
Q

Impeller specific speeds usually lies between

A

400-20K based on impeller type

23
Q

Pump impellers classification

A

Centri or radial
Mixed flow
Axial

24
Q

Specific speeds between 400 and 4000

A

Centri or radial

25
Q

Ns between 4K to 9K

A

Mixed flow

26
Q

Ns above 9K

A

Axial

27
Q

Ns below 1k, what should be used?

A

Multi-stagr pump

28
Q

Used for high head at low flow rate

A

Reciprocating pumps or Positive displacement

29
Q

T/F: Selection of pump can be separated from the design of the complete piping system

A

F

30
Q

Pressure drops required across control valve will be function of?

A

Valve design

31
Q

Control valve and pump should be sized together as unit T/F

A

T

32
Q

Control valve pressure drops based on rough guide should be taken at least ____ of the total dynamic pressure drops through the system with a minimum value of ____

A

30%
50 kPa

33
Q

A good rule of thumb for each control valve must allow __ kPa pressure drop

A

70

34
Q

A valve should be sized for a maximum flow rate of _ above normal stream flow rate

A

30%

35
Q

Newtonian liquids using the chart

A

Constant fluid viscosity
Constant density

36
Q

Viscosity is a function of shear stress

A

Non-newtonian

37
Q

When gas flows through a pipe, the ____ is a function of pressure and determined by pressure drop

A

Gas density

38
Q

Liquid-solid mixtures that do not settle rapidly are usually treated as?

A

Nom Newtonian fluids

39
Q

If particle is less than 200 microns

A

Non Newtonian fluids

40
Q

Gas solid mixture are comnonly encountered in?

A

Pneumatic converying

41
Q

Any obstruction to flow will generate ___ and cause ___

A

Turbulence and pressure drop

42
Q

Pipe fittings causes an/a ____ in pressure drop

A

Increase

43
Q

Pressure loss is due to?

A

Flow measurement equipment

ChE Design (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions