Study Unit 5

Question 1

A

Answer 1

1st: Analyser
2nd: Alarm

Question 2

C

Answer 2

2nd: Controller

Question 3

F

Answer 3

1st: Flow rate

Question 4

G

Answer 4

1st: (User’s choice)

Question 5

H

Answer 5

2nd: High (alarm)

Question 6

I

Answer 6

1st: Current
2nd: Indicator

Question 7

J

Answer 7

1st: Power

Question 8

L

Answer 8

1st: Level
2nd: Low (alarm)

Question 9

LL

Answer 9

1st: Liquid level

Question 10

P

Answer 10

1st: Pressure

Question 11

Q

Answer 11

1st: Heat (energy) flow

Question 12

R

Answer 12

Recorder

Question 13

S

Answer 13

1st: Speed
2nd: Switch

Question 14

T

Answer 14

1st: Temperature
2nd: Transmitter

Question 15

What is a process unit?

Answer 15

Process equipment where mass and heat transfer is physically taking place

Question 16

Input and output of process units?

Answer 16

Input: Feed streams
Output: Product streams

Question 17

Input and output of process?

Answer 17

Single input: Manipulated stream (variable)(MV)
Output: Measurable variables (Process variables)(PV)
Any other inputs: Disturbances

Question 18

How does an open loop control system function?

Answer 18

Manually

Question 19

How does a closed loop control system function?

Answer 19

Automatically

Question 20

Why is process control necessary?

Answer 20

Safety
Product specifications
Environmental regulations
Operational constraints
Economics

Question 21

Surge tank level control system

Answer 21

Level transmitter (LT)
Liquid level controller (LLC)
Control valve

Question 22

LLC

Answer 22

Liquid level controller
Compares level reading from LT with desired level/set point (SP) and then transmits this information on to the control valve

Question 23

Control valve

Answer 23

Final control element

Valve percent opening is adjusted to correct for any deviations from the set point

Question 24

Six elements of process control

Answer 24

1. Process
2. Transmitter/Sensor
3. Transducers (not shown in I/O block diagram)
4. Transmission lines
5. Controller
6. Final control element

Question 25

Transducer

Answer 25

Electronic equipment that converts the pressure/temperature/flow signal from the sensor into an electrical signal or vice versa.

Question 26

For industrial process control elements what current loops are used for analog signaling?

Answer 26

Analog 4-20 mA current loops | 0-10 bar

Question 27

Dead-zero

Answer 27

0 mA | Indicative of a loop failure

Question 28

Live-zero

Answer 28

4 mA | Corresponds to the minimum value of 0 bar

Question 29

Full scale value of analog current loop

Answer 29

20 mA | 10 bar

Question 30

Transmission lines

Answer 30

Communication lines and equipment used to channel information to the necessary equipment

Question 31

Controller

Answer 31

Controllers are used to determine the size of the corrective action that should be taken to achieve the required outcome

Question 32

Types of control systems

Answer 32

Distributed Control System (DCS) Programmable Logic Controller (PLC) Supervisory Control and Data Acquisition (SCADA)

Question 33

DCS

Answer 33

Distributed Control System

Question 34

PLC

Answer 34

Programmable Logic Controller

Question 35

SCADA

Answer 35

Supervisory Control and Data Acquisition

Question 36

Final control element

Answer 36

Execute the actions determine by the controller

Question 37

What is included in a PFD?

Answer 37

``` Flow of chemical materials Equipment used in process - Utilities (process piping) - Major equipment without showing details - Major process control loops ```

Question 38

FA

Answer 38

Flow Alarm | Indicating flow alarm

Question 39

FC

Answer 39

Flow Controller | Flow control

Question 40

FE

Answer 40

Flow Element | Flow sensor

Question 41

FI

Answer 41

Flow Indicator | Flow indication

Question 42

FIC

Answer 42

Flow Indicating Control | Controling and indicating of flow

Question 43

FR

Answer 43

Flow Recorder | Recording of flow

Question 44

FT

Answer 44

Flow Transmitter | Transmitting flow signal

Question 45

Why is a P&ID so important?

Answer 45

Shows information to design and build plant Forms the basis for process safety studies Forms the basis for semi-definite cost estimates of what the plant will cost

Question 46

HAZOP

Answer 46

Hazard and operability study

Question 47

What does a P&ID contain?

Answer 47

- Process piping, sizes and identification (indicates to pipe designers the material requirements) - Valves - Vents, drains, special fittings, sampling lines, reducers - Flow direction - Mechanical equipment -

Question 48

Piping class

Answer 48

Defines the type of material, Flange ratings, pipe wall thickness and what fittings to use