Homework Pt.12 Level 9

Question 1

Which of the below purposes of electric heat tracing “do not” apply?

Answer 1

a. provide freeze protection
b. eliminate the use of thermal insulation✅
c. maintain the temperature of process fluids
d. Prevent condensation in piping systems

Question 2

Which type of temperature control that would most likely be used for process lines that carry syrup is?

Answer 2

Narrow

Question 3

In a typical power distribution scheme Branch circuit, _______
breakers are used to apply
operating voltages to the power connection boxes of heat tracing circuits.

Answer 3

Ground Fault Interrupting

Question 4

Which cable Is used for applications that require a heat output that varie With changes in the temperature of the air or other medium surrounding the cable?

Answer 4

Self-regulating heat tracing

Question 5

Which control method is used for heat tracing systems uses a programmable controller connected to remote temperature input modules and contactor control modules to regulate one or more heat tracing cables?

Answer 5

Proportional ambient-sensing control

Question 6

In dead-leg control, what type of flow condition exists in the dead leg?

Answer 6

No flow

Question 7

The main function of special ground-fault circuit breakers in a heat tracing system is to protect the____

Answer 7

Equipment

Question 8

What type of temperature-sensing device is generally used to monitor the temperature of the pipe for heat-tracing control purposes?

Answer 8

RTD

Question 9

What is Powerline carrier technology?

Answer 9

uses frequency-Shift keying to decode digital data on the Powerline network

Question 10

When installing heat-tracing cables, their cold leads must be positioned so that they penetrate the piping thermal insulation in?

Answer 10

the lower 180-degree segment of the pipe

Question 11

The most cost-efficient type of steam heat-tracing system likely to be installed in a new facility is a channel/tube______
system

Answer 11

Channel/tube Conduction

Question 12

Does propylene glyco have
better heat transfer efficiency than ethylene glycol?

Answer 12

No- Ethylene glycol does

Question 13

The concentration of chemical additives added to a system to provide for burst protection is

Answer 13

less than is needed to provide for freeze protection

Question 14

The general term used to describe the covering placed directly over the insulation materials Is?

Answer 14

Lagging

Question 15

In some heat tracing installations covered with insulation, aluminum foil is wrapped over the heat tracing line before insulating the piping to _______

Answer 15

Increase the radiation heat transfer

Question 16

A protective device that can be installed at the inlet of a pressure element to prevent rapid pressure changes in the input to the instrument is called a

Answer 16

Snubber

Question 17

The main reason to blow down instrument air lines is to remove_______from the lines

Answer 17

Moisture/Debris

Question 18

Why does water vapor begin to condense inside the receiver of a compressed air system?

Answer 18

Because the air in the receiver may cool down to the dew point

Question 19

Blowdown valves should never be opened too wide because______

Answer 19

the extreme pressure drop could cause water to freeze in the line

Question 20

The first consideration in preparing to blow-down signal lines is to consider the?

Answer 20

purpose of the instrument in the process