Chapter 104

Question 0

The feed water control switch is commonly operated by?

Answer 0

low-water fuel cut-off float

Question 1

Feed water supply to most steam boilers is usually controlled by?

Answer 1

Float switch

Question 2

List two types of Mercury pole switches:

Answer 2

Single/double pole

Question 3

What happens at the highest operating level of the water in the boiler?

Answer 3

Feed water supply switch opens. Stopping the power supply to the control valve or supply pump. (Stops water supply to boiler)

Question 4

When the water level is insufficient or pump fails to start?

Answer 4

Fuel cut-off switch opens and cuts off the power to the fuel valve and sounds an alarm (double pole Mercury switch)

Question 5

What does ASME, Section IV cover?

Answer 5

Low water fuel cutoff.

Question 6

In a steam heating plant where does the steam give up most of its heat?

Answer 6

Radiators, convectors

Question 7

If control of the feed water supply is the primary function of the cut-off device what is required by code?

Answer 7

A second cut-off

Question 8

Second source heating boiler water is controlled by the low water fuel cut of device in two ways:

Answer 8

Electric feeder valve, float operated mechanical feeder valve

Question 9

Hartford loop return line is connected where on a steam heating boiler?

Answer 9

It’s connected to the loop at the lowest safe water level

Question 10

What kind of pump requires a steaming heating boiler to be equipped with a Hartford loop?

Answer 10

Non positive displacement (centrifugal pump)

Question 11

If multiple heating boilers require water which valve will open the pump switch to shut it off?

Answer 11

The valve that closes last

Question 12

An undersized condensate receiver may cause what?

Answer 12

Loss of condensate to the sewer

Question 13

What’s the general rule for the size of a condensate receiver tank?

Answer 13

Be able to hold enough condensate equivalent to 20-30 minutes of normal water evaporation in the boiler

Question 14

When should a larger condensate receiver tank be used?

Answer 14

Systems extended over larger area

Question 15

What is a disadvantage of the float mechanism feeder?

Answer 15

Unsteady valve operation due to violent fluctuations of returning condensate

Question 16

What will cause grooving in the condensate receiver?

Answer 16

Carbon dioxide

Question 17

How can an operator get rid of carbon dioxide from ruining the condensate return lines?

Answer 17

Filming amines that will coat the metal

Question 18

A float operated mechanical feeder valve should:

Answer 18

Not open until the level is well below the feed pump cut-in level

Question 19

Equalizing lines on a condensate receiver float chamber:

Answer 19

Will dampen water level fluctuations

Question 20

Bleeding water out of the control line on the condensate receiver will result in what?

Answer 20

Pressure drop in the control line

Question 21

A feed water makeup supply should?

Answer 21

Be able to satisfy firing rate

Question 22

Neutralizing amines:

Answer 22

Raise the pH of condensate

Question 23

A condensate receiver low water cut-off will?

Answer 23

Stop the pump in order to prevent damage

Question 24

A float operated mechanical feeder valve should?

Answer 24

Not open until the level is well below the feed pump cut-in level

Question 25

A thermal element, used on hot water boilers is capable of sending temperature and?

Answer 25

Converting it to a pressure signal