Low Pressure Boilers Chapter 9

Front 1

Hot water heating systems produce heat more consistently than steam heating systems.

Back 1

True

Front 2

Hot water heating systems require less water than steam heating systems.

Back 2

False

Front 3

The natural circulation hot water heating system uses circulating pumps to transport water in the system.

Back 3

False

Front 4

Water becomes less dense as it is heated.

Back 4

True

Front 5

The natural circulation hot water heating system uses a compression tank to absorb pressure changes.

Back 5

False

Front 6

Natural circulation hot water heating systems are commonly used in large contemporary buildings.

Back 6

False

Front 7

Floor-mounted circulating pumps are used in small plants.

Back 7

False

Front 8

Line-mounted circulating pumps operate intermittently, depending on plant requirements.

Back 8

True

Front 9

The forced circulation hot water heating system is vented to the atmosphere.

Back 9

False

Front 10

The aquastat controls the starting and stopping of the burner on a hot water boiler.

Back 10

True

Front 11

The flow control valve prevents natural circulation when water is not pumped in the forced circulation hot water system.

Back 11

True

Front 12

The pressure-reducing valve is used to prevent overpressure of water supplied to the expansion tank.

Back 12

False

Front 13

Diverter fittings are used to vent air from the heating units.

Back 13

False

Front 14

Stop valves before and after the pressure-reducing valve allow servicing of the pressure-reducing valve.

Back 14

True

Front 15

The three-way mixing valve blends water returning from the heating units with supply water from the boiler.

Back 15

True

Front 16

All boilers are manufactured in conformance with Section I or IV of the ASME Boiler and Pressure Vessel Code.

Back 16

True

Front 17

An aquastat controls the burner by sensing steam pressure in a hot water boiler.

Back 17

False

Front 18

The strainer in the pressure-reducing valve should be inspected periodically for scale formation.

Back 18

True

Front 19

The compression tank is normally full of water to feed into the boiler during a low water condition.

Back 19

False

Front 20

The relief valve should be located on the highest part of the boiler.

Back 20

True

Front 21

Relief valves should be manually tested every 30 days as recommended by the ASME Code.

Back 21

True

Front 22

Relief valves should discharge into the return line feeding into the circulating pump.

Back 22

False

Front 23

A temperature-pressure gauge indicates temperature in the compression tank.

Back 23

False

Front 24

Hydrostatic pressure is expressed in pounds per square inch (psi).

Back 24

True

Front 25

Air controls are used to allow water to drain from the compression tank.

Back 25

False

Front 26

Air removed from the boiler water is diverted to the compression tank in a forced circulation hot water heating system.

Back 26

True

Front 27

An aquastat commonly has a temperature differential preset by the manufacturer.

Back 27

True

Front 28

The aquastat temperature differential setting controls the starting and stopping of the circulating pump.

Back 28

False

Front 29

Two diverter fittings may be required for heating units above the supply line where resistance to circulation is high.

Back 29

True

Front 30

Hot water heating systems require special hot water boiler accessories.

Back 30

True

Front 31

Water conveys approximately one-___ the amount of heat that steam conveys.

Back 31

fifth

Front 32

A hot water heating system operates at ___ the steam heating system.

Back 32

a lower temperature than

Front 33

In a natural circulation hot water heating system, the ___ functions as a relief valve.

Back 33

expansion tank

Front 34

___ pressure is water pressure per vertical foot exerted at the base of a column of water.

Back 34

Hydrostatic

Front 35

In a remote temperature-monitoring system, the burner is controlled based on ___.

Back 35

outside temperature

Front 36

Steam boilers are classified as "high pressure" if steam pressure exceeds ___ psi.

Back 36

15

Front 37

A flow control valve functions similarly to a(n) ___ valve to prevent natural water circulation.

Back 37

check

Front 38

Hot water boilers operating with a 250°F water temperature and ___ psi water pressure or less are classified as low pressure.

Back 38

160

Front 39

Hot water boilers can be ___ boilers.

Back 39

firetube, watertube, & cast iron sectional

Front 40

A hot water boiler relief valve is rated in ___ relieved per hour.

Back 40

BTU's

Front 41

A steam boiler safety valve is rated in ___ relieved per hour.

Back 41

pounds of steam

Front 42

A relief valve must be built according to the ___.

Back 42

ASME Code

Front 43

The relieving pressure of a relief valve on a low pressure hot water boiler cannot exceed ___ psi.

Back 43

160

Front 44

The two types of low water fuel cutoffs normally used on hot water boilers are the ___-type and the probe-type cutoffs.

Back 44

float

Front 45

The ___ tank is normally half full of water to maintain the correct water level in the forced circulation hot water heating system.

Back 45

compression

Front 46

Section VI of the ASME Code recommends relief valves be manually tested ___.

Back 46

every 30 days

Front 47

The ___ protects the hot water heating system from exceeding the MAWP.

Back 47

relief valve

Front 48

The ___ controls the starting and stopping of the burner by sensing the temperature in the hot water boiler.

Back 48

aquastat

Front 49

The temperature-pressure gauge indicates the temperature and pressure of the water ___.

Back 49

leaving the boiler

Front 50

___ direct the flow of hot water supplied to and returned from the heating units.

Back 50

Diverter fittings

Front 51

A ___ prevents natural circulation when hot water is not being pumped through the forced circulation hot water system.

Back 51

flow control valve

Front 52

A pressure-reducing valve reduces the pressure of city water to approximately ___ psi.

Back 52

12 to 18

Front 53

A(n) ___ allows bleeding of trapped air in a heating unit.

Back 53

air vent

Front 54

If the compression tank is allowed to fill with water, pressure will increase, causing the ___.

Back 54

relief valve to open

Front 55

Larger compression tanks are equipped with a ___ for determining the compression tank water level.

Back 55

gauge glass