Brainscape's Knowledge GenomeTM

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


See full index

Danica’s Steamfitter III Review > Controls Part B > Flashcards

Controls Part B Flashcards

1
Q

What are the three primary reasons for sensing and measuring variables?

A

To indicate, record and control

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

What does it mean if a primary sensing element is remote located?

A

Remote can main panel or board mounted. The sensing device can be located in a process line and the indicator or recorder portion can be located in a control room.

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

If a primary sensing element is classified as integral, where would the sensing device and indicator be located?

A

On the process line

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

What are the four main types of variables to be measured?

A

Temperature, pressure, liquid level and flow rate.

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

Is a Bellows actuator filled with a liquid with a high boiling point or a low boiling point?

A

Low boiling point

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

What is the purpose of a thermowell?

A

To protect thermometers and other sensing bulbs from high external pressures, and possible damage.

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

What is an averaging elements purpose?

A

To get the reading of the average temperature across the face of a large air heating coil. Differences and temperature at various points are averaged out as a single pressure in the tubing.

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

The operation of what element depends on the principle that dissimilar metals expand at different rates when heated?

A

Bimetal element

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

A helix type bimetal strip would be used in what situation?

A

To obtain considerable rotation of a pointer on a scale, and spread the scale for maximum accuracy and sensing temperature

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

What type of element consists of a tube with a high rate of expansion over a rod with a lower rate of expansion?

A

Rod and tube element

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

The thermal electric pyrometer method of sensing ____________ is created by using dissimilar metals that when heated will generate a DC current in millivolts.

A

Temperature

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

What does a monometer measure?

A

The difference between two pressures or the differential pressure measurement

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

Are manometers able to measure vacuum?

A

Yes

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

If a longer scale of measurement is required for a more accurate reading what type of monometer is recommended?

A

Incline tube monometer

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

What does a compound gauge measure?

A

A compound gauge can indicate both PSIG (pressure) and inches mercury (vacuum) on the same dial face.

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

What is used to protect a Bourdon tube from damage due to exposure to steam?

A

A siphon pigtail or a U trap is used between the gauge and the steam. water should be added to the pigtail to build a water seal

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

Can a diaphragm element indicate vacuum?

A

Yes

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

What is the simplest form of liquid level measurement?

A

Directly, usually with the aid of a sight glass or other visual level indicator

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

When using a diaphragm actuated differential pressure transmitter (DP cell) what pressure is on the high-pressure side and the low pressure side of the diaphragm?

A

The tanks head pressure would be on the high-pressure side of the diaphragm and the low pressure side is vented to atmosphere.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is required to measure the rate of flow using the differential pressure method in a pipeline?

A

Some form of restriction placed in the pipeline to create a pressure drop.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

When an orifice plate is used to restrict flow in a pipeline , the lowest pressure occurs at the point where the fluid has the smallest cross-sectional area. What is the point called?

A

Vena contracta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

After a fluid passes through an orifice plate and the vena contracta, the pressure begins to increase but never fully recovers due to what?

A

Permanent loss of energy occurs due to friction and turbulence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

An orifice plate with a straight or bevelled edge is installed with the flat face oriented upstream, or downstream?

A

Upstream

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

On an orifice plate, which way is the stamped face normally installed?

A

Normally upstream

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What size of pipe are flange taps generally used on?

A

2 inch and larger

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

On a full flow or pipe tap where are the connections for the transmitter located?

A

They’re located on the actual process line, not on the orifice flanges. The upstream high-pressure tap is 2 1/2 pipe diameters from the face of the orifice plate and the downstream, Low pressure pipe tap is located eight pipe diameters from the face of the orifice plate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Where are the connections for the transmitter for a Vena contracta or radius tap method??

A

The connections for the transmitter are located on the actual process line, not on the orifice flanges. the high-pressure upstream pipe tap is one pipe diameter upstream of the face of the orifice plate, and the low pressure downstream pipe tap is a half pipe diameter from the face of the orifice plate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Vena contracta or radius taps are limited to what pipe sizes?

A

6” and larger

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Laminar flow is essential upstream of an orifice plate. The general rules are:
_____ pipe diameters if the disturbance is due to flanges, collars, wide, open gate valves, reducers, elbows, or other changes in direction provided the flow is all in the same plane (horizontal).
_____ pipe diameters are required if a fitting changes the flow in two planes (vertical to horizontal).
_____ diameters required if the disturbance is caused by PRV’s, control valves or similar regulators.

A

10
50
75

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

How many pipe diameters are sufficient before a disturbance on the downstream side after an office plate?

A

5

31
Q

Straightening veins are how many pipe diameters from the high-pressure tap connection?

A

Six pipe diameters minimum

32
Q

How many pipe diameters from the straightening vein to the nearest upstream disturbance?

A

Four pipe diameters minimum

33
Q

What element senses impact and static pressure at the same instant?

A

Pitot tube

34
Q

Do flow nozzles and Venturi tubes produce less permanent pressure drop or more permanent pressure drop than an orifice plate?

A

Less

35
Q

What are the disadvantages of a flow nozzle or Venturi tube versus an orifice plate?

A

Bulkiness and higher cost

36
Q

A differential pressure cell can be connected from the high-pressure side upstream tap of an orifice plate and the low pressure side to the downstream tap but what does it measure?

A

Differential pressure not flow.

37
Q

Using a DP cell across the high and low pressure sides of an orifice plate requires what to obtain a flow reading?

A

A mathematical function instrument called a mechanical Square root extractor.

38
Q

What are three and five block valve manifold used for?

A

For isolating, purging, venting, and bringing a piece of control equipment online using close tolerance needle valves.

39
Q

What type of metre consist of a tapered tube in which a float or rotor can move up and down freely the fluid being measured flows through the tube from the bottom to the top, and this causes the float to take position in the tube.

A

Rotameter or variable area metre

40
Q

Which type of metre uses the velocity of a moving liquid or gas to react against the propeller type blade, causing the blades to turn, and the rotation of each blade is measured by the electricity it creates?

A

Turbine flow metre

41
Q

What type of flow metre offers no flow restriction, but is the most expensive used for flow measurement?

A

Magnetic flow meter

42
Q

Primary elements use what range of instrument air and electric signal?

A

3 to 15 psi or 4 to 20 mV

43
Q

What range of air pressure does a final control element use?

A

15 to 25 psi

44
Q

Heading downstream off of an air compressor tank, would the air filter be first or the pressure reducing valve?

A

Air filter

45
Q

What is the industry standard dewpoint?

A

-40C

46
Q

For moisture removal purposes, would you size a compressor with a higher operating pressure rating or an adequate operating pressure rating then is required for air supply purposes alone?

A

Higher

47
Q

Under what condition would a mechanical air dryer be required?

A

When compressed air piping is run along outside walls or outdoors.

48
Q

What does a hygrometer measure?

A

Moisture content in the instrument air

49
Q

What type of dryer consists of two identical chambers, valves, a timer and their use is alternated?

A

Desiccant or chemical dryer

50
Q

Heatless regeneration of the desiccant means what?

A

No heat is required to drive moisture from the desiccant being dried

51
Q

What are the two types of desiccants?

A

Silica gel beads and activated alumina

52
Q

An after cooler is a heat exchanger type of equipment, used to cool the air temperature to its dewpoint, for what reason?

A

To reduce moisture in the air

53
Q

Where is an intercooler located?

A

Between the cylinders in an air compressor

54
Q

The _______ __________is to prevent dust, or other airborne contaminants from entering the intake valves of the compressor.

A

Intake filter

55
Q

To maintain the life of the compressor and the warranty the compressor oil used must be recommended by whom?

A

The manufacturer

56
Q

Limiting _____________ in compressed air piping as of the upmost importance.

A

Condensation

57
Q

Along with the air filter, what other piece of equipment is located in the piping between the compressor and the pressure reducing valve?

A

The moisture condenser

58
Q

To decrease moisture in the system, would you be required to increase the air temperature or decrease air temperature?

A

Decrease

59
Q

Who are the ISA and what do they write an issue standards for?

A

International Society of automation writes and issues standards for all pneumatic instrumentation systems.

60
Q

When troubleshooting the sensing and measuring variables, what element would you be primarily concerned with?

A

The primary element

61
Q

When a pressure gauge is located on the process piping is it classified as remote mounted or integral mounted?

A

 integral mounted

62
Q

The thermometer is designed to measure:
1. absolute temperature
2. molecular movement

A
  1. Molecular movement.
63
Q

The sensing element normally used in a pressure gauge is what?

A

Bourdon tube

64
Q

On what law do floats operate?

A

Buoyancy laws

65
Q

Which type of flow measuring device is the only accurate measure of volume?
A. Electromagnetic
B. Positive displacement
C. Orifice plate

A

B. Positive displacement.

66
Q

Which type of metre is mainly used used as an indicating device?
A. Turbine flow meter.
B. Rota meter.
C. Magnetic flow meter.

A

B. Rota meter.

67
Q

How is moisture introduced into the pneumatic control system?

A

Through the intake filter

68
Q

The air compressor is controlled by a:
A. Pressure switch.
B. Float switch.
C. Power switch.

A

A. Pressure switch.

69
Q

Is the aftercooler located before or after the receiver?

A

Before the receiver

70
Q

What type of air drying technique uses a cooling tower?
A. Chemical dryer
B. Moisture condenser.

A

B. Moisture condenser.

71
Q

What is the primary cause of noise transmitted from the compressor?

A

Vibration

72
Q

What is the type of piping or tubing found on large pneumatic instrumentation systems?

A

Galvanized pipe

73
Q

Before filling and testing a system that contains float type metres what should you do?
A. Check the level.
B. Remove shipping materials.
C. Install plugs.

A

C. Install plugs.

Danica’s Steamfitter III Review (12 decks)

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