Fourth Year - Block F Hydronic Heating Systems[][][][][][][][][][][][][][][][][][][][][][][][][][][] Flashcards
1
Q
What are the four main hydronic heating piping layouts that are commonly installed?
A
One-pipe series loop.
One-pipe monoflow/Diversion-tee.
Two-pipe direct-return (AKA first fed first return).
Two-pipe reverse-return (AKA first fed last return).
2
Q
What is the purpose of an expansion tank in a hot water heating system and where should it be located?
A
Regulates pressure / Thermal expansion.
(Prevents pressure relief valve from going off when the boiler fires up)
Located upstream from the system pump[][][][][][][][][][][][][][][][][][][][][][][][][][]
3
Q
Where is the best location for the circulator to be installed on a hydronic heating system?
A
On the supply piping leaving the boiler.
(It should be downstream of the expansion tank).
On the return piping leaving the boiler[][][][][][][][][]]
4
Q
What is the pressure relief valve in a residential boiler usually set to?
A
30 psig.
5
Q
Where is the pressure relief valve in a residential boiler usually located?
A
On the boiler.
6
Q
How much volume must the relief valve be able to relieve if necessary?
A
100% rating of the boiler.
7
Q
What would cause the pressure relief valve to start dripping?
A
Waterlogged expansion tank.
8
Q
What is make-up water on a hydronic heating system?
A
Water that is introduced into the closed hydronic system.
9
Q
What is another name for the pressure reducing valve that reduces the pressure before it gets into the system?
A
Feed water valve.
10
Q
What is the pressure in a residential hydronic heating system usually set to?
A
Between 12 and 20 psig.
11
Q
What is a flow check valve and where is it located?
A
Prevents the unwanted flow of water through a system when the burner is not on.
It’s located on the supply leaving the boiler[][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][]]
12
Q
What is the difference between a flow check and a flow switch?
A
Flow check is for gravity circulation and flow switch is a proving switch for the pump.
13
Q
Where would you install a backflow preventer in a boiler system?
A
In the make-up water line on the boiler.
14
Q
What is the typical backflow preventer installed in a residential boiler?
A
Watts 9-D.
15
Q
Where would the PRV be installed in relation to the boiler?
A
On the make-up water line.
It should be installed after the backflow preventer.
16
Q
What should the PRV be set at in a typical residential application?
A
Between 12 and 20 psig.
17
Q
What is an air scoop and where is it located?
A
An air/water seperator.
Attached to the expansion tank which will be located upstream of the system pump.
(This would be where the temperature is the highest and the pressure is the lowest).
18
Q
What is the “R” value of a material?
A
Hours / Btu / Degrees F / Feet Squared.
19
Q
What is the “U” value of a material?
A
Btu’s / Hours / Degrees F / Feet Squared.
20
Q
What does the design temperature difference (DTD) refer to?
A
The temperature difference between the inside of the building and the outside temp.
21
Q
How do you calculate flow rate required in a hydronic heating system?
A
GPM = Btuh / 500 x Change in Temperature.
22
Q
What do the terms “fire tube” and “water tube” refer to when dealing with boilers?
A
Fire tube: Flue gas travelling through the tubes surrounded by water.
Water tube: Water travelling through the tubes surround by flue gas[]
23
Q
What is a conventional boiler?
A
Products of combustion remain relatively hot and do not condense.
24
Q
What is a condensing boiler?
A
Most of the heat is removed from the products of combustion and the products of combustion cool down enough to condense.
25
What boiler is more efficient?
Condensing boiler or conventional boiler.
Condensing boiler.
The removed heat is reused.
26
Is there any other factor to be considered when dealing with a condensing boiler?
The condensate is acidic.
Must be neutralized before entering the drainage system.
27
What extra component would you require if you used boiler water to heat domestic hot water?
Heat exchanger or indirect storage tank.
(You need to seperate boiler water from drinking water).
28
What is the difference between a gravity hot water heating system and a closed loop hydronic system containing a circulator?
Gravity hot water heating system: Larger pipe / May be open at top / No pump.
Closed loop hydronic system: Pressurized / Pump / Smaller pipe[][][][][][][][][][][][]]
29
Which two variables determine how a circulator is sized in a hyrdonic heating system?
Flow rate (Gallons per minute).
Total head loss (Total head in feet).
30
What is the minimum return water temperature for a non-condensing boiler?
140°F.
31
What is a low mass boiler?
Doesn't contain much water in the heat exchanger.
32
What must be proven to be working on a low mass boiler before the burner will fire?
Flow.
33
What proves that the pump is working on a low mass boiler?
Flow switch.
34
Where is the flow switch on a low mass boiler located?
On the supply leaving the boiler.
35
What is a chiller?
A machine that removes heat from a liquid.
36
What type of piping connection does a chiller usually have?
Flanged connections with flexible connectors.
37
What is an important consideration when determining the location of a chiller?
Isolation valves.
(To allow for maintenance).
38
What is a cooling tower?
Removes waste heat to the atmosphere.
39
How would the water level be maintained in the reservoir of a cooling tower?
Float switch.
40
Where should the low water cut off (LWCO) be installed in a hot water boiler?
In the supply piping above the boiler.
41
Where should the low water cut off (LWCO) be installed in a steam boiler?
On the boiler.
(Generally about 1 to 2 inches above the highest water tubes).
42
How do you cut glass sight tubes?
Score the entire tube and then gently tap or slightly heat up.
43
Where would you install outlets from a ducted cooling system?
In the ceiling.
44
Where, and at what height, is the best location to install a thermostat in a room?
Five feet above ground.
Interior wall[][][][][][][][][][][]]
Not in direct sunlight[][][]
Area where good air flow is present.
45
When doing routine boiler maintenance, you notice that the water in the boiler system is black and smelly. What could be concluded from this? What could you could you conclude if the water was clear?
Black and smelly (brackish): Everything is okay.
Clear: A leak in the system which would be allowing more clean fresh water in.
46
A unit heater is installed in a shop and is intended to supply heat to the shop area. The shop has a loading dock with a bay door. In which direction should the unit discharge?
Across the bay door.
47
The domestic hot water in a residence is heated by running boiler water through a water to water heat exchanger. What valve is needed on the domestic side in order to ensure the water does not become too hot?
Tempering valve.
48
A house is fitted with a radiant panel heating system. You are to install balancing valves in the system. Where would you install them?
On the return header.
49
What is a wild loop? When installing a wild loop, what component is generally installed in conjunction with it?
Acts like a pressure differential valve.
A globe valve was installed in the loop to allow for throttling.
50
A homeowner decides to heat his domestic hot water using a solar heating system. What does the homeowner need to install in his system in order to prevent contamination of the domestic hot water?
Heat exchanger.
51
A boiler is installed in a residence and the domestic heating system includes low-temperature radiant floor heating. What is required on the low-temperature heating side?
Mixing valve.
52
A direct return heating system is being used in a building. The heat in the rooms is not controlled individually but by a central thermostat. It is noticed that one of the rooms is hotter than the others. How can this issue be rectified?
Adjust the balancing valve.
53
How many btu's are in one cooling ton?
12,000 Btu's.
54
What is a triple duty valve?
Balancing Valve + Check Valve + Shut Off Valve.
55
How is cooling pipe (refridgeration pipe) put together?
Brazed.
56
Where would you install the cooling coil in a cooling system in relation to the fan?
The fan must come before (upstream of) the cooling coil.
57
What is the required safety valve rating for a low pressure steam boiler?
15 psig.
58
How do you grade a steam line in a steam heating system?
Down away from the boiler to the steam trap/dirt leg (1" in 20 ft) in direction of steam flow.
59
Both elements on a domestic hot water tank are working normally. What would be the cause of no hot water?
Broken dip tube.
Calcified elements.
60
If you have a PRV in a boiler system set at 15 psig, and the system pressure is only 7 psig, what is the problem?
PRV.
61
How does a steam trap operate?
Senses the difference in density between water and steam.
62
A low pressure steam boiler has a set operating pressure 5 psig below the maximum allowed by the ASME code. The differential of the pressuretrol is 4 psig. What is the cut-in pressure?
6 psig.
(Maximum allowed by code is 15 psig).
63
Which location is most suitable for the installation of a cooling tower?
Outside in a ventilated area.
64
What type of components might be installed with all indoor fuel oil tanks?
Drain.
Liquid level guage.
Pump[][][][][][][][][][][][]
Vent whistle alarm.
65
What is installed on a fuel oil system to remove suspended particles and prevent clogging of nozzles?
Screen.
66
What would be the most likely cause if "no-heat" complaints were being recieved from the occupants of the top floor of an apartment building?
Air lock.
67
What is the glycol formula?
System capacity x (required glycol % - current glycol %)
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
(100 - current glycol %)
68
Where are the inlet and outlet connections made on a steam radiator?
Top in, bottom out.
69
Where are the inlet and outlet connections made on a hot water radiator?
Bottom in, top out.
70
Where should the relief valve be piped to in a low pressure steam system?
To a safe place.
71
What is them minimum size blow down drain in a low pressure steam system?
3/4".
72
Heat exchanger is made from cast iron is the definition of?
Cast iron boiler.
73
Area where combustion occurs is the definition of?
Combustion chamber.
74
Water droplets which form from flue gases that have temperatures less than its dew point (typically 130 Degrees F) is the definition of?
Condensate.
75
Heat exchanger is made from copper is the definition of?
Copper tube boiler.
76
A storage vessel which recieves heat from an external heat source is the definition of?
Indirect-fired.
77
Boiler whos heat exchanger contains 15 usg or less is the definition of?
Low mass boiler.
78
Small added resistance to the thermostat designed to "trick" the thermostat into responding quicker to ambient temperatures is the definition of?
Heat anticipator.
79
Type of heat transfer typically through solids is the definition of?
Conduction.
80
Heat required to change to state of a substance from solid to liquid or liquid to gas. Also reffered to as "hidden heat" is the definition of?
Latent heat.
81
What temperature range do most hydronic heating systems operate?
32 - 250°F.
82
What is the temperature design drop with a typical hydronic system?
20°F.
| (Infloor is 10°F.)
83
List five heat sources used for hydronic systems?
Boiler.
Electrical resistance.
Geothermal[][][][][][][][]]
Heat Pump[][][][][][][][]]
Solar[][][][][][][][][][][][][][]
84
Is a fire tube boiler typically high or low mass?
Typically high mass.
85
What do we need to be aware of with low mass boilers and how can we protect against that issue?
Need to have a flow switch located downstream of the primary circulator.
(This ensures that the water is flowing through the heat exchanger of the boiler prior to burner starting).
86
What temperature ranges do condensing/conventional boilers operate in?
Condensing boiler: Less than 190 Degrees F.
Conventional boiler: Greater than 190 Degrees F.
87
Name three methods of eliminating air from a hydronic system?
Automatic/manual air vents.
Chemical additives[][][][][][][][]
Micro bubblers[][][][][][][][][][][]
88
Describe how you would help meet the demands of different areas with different heating demands within the project?
Zoning.
89
The location of the expansion tank attachment to the hydronic system. The pressure at this point does not change regardless of whether the system circulator is on or off is the definition of?
Point of no pressure change.
90
These terms refer to the difference between the actual room temperature and the operating differentials is the definition of?
Undershoot and overshoot.
91
Why is it important to size the circulator correctly?
Cost.
Electrical usage.
Head pressure added to system.
92
Is that heating load factor which is based upon the heat loss of an area. It is the heat loss that the system is designed to replace is the definition of?
Design heating load.
93
Layers of heated air or water in a given volume is the definition of?
Stratification.
94
What pressure should the expansion tank be set for?
The static pressure of the system.
95
How are heat sources classified?
Condensing, conventional.
Heat exchanger type[][][][][]
Volume of heat exchanger.
96
Where is the best place to eliminate air from your system?
Point of highest temperature.
Point of no pressure change.
97
Tees with an integral venture is the definition of?
Mono-flow tees.
(Used in single series or split series circuits).
98
A large volume of air trapped in a heating system which prevents the circulation of water through a particular portion or zone is the definition of?
Air lock.
99
That pressure required to keep entrained air bubbles small enough to travel with the water within the heating system is the definition of?
Vapour pressure.
100
What utilizes a mechanical means (fan) to force the movement of air across a fin or coil?
Forced convection heater.
101
Which piping system absolutely needs balancing valves?
Direct return.
102
Which piping system is most associated with manifolds?
Home-run systems.
103
Which type of heat source utilizes gasification?
Solid fuel (wood).
104
What is the maximum operating temperature of a low temperature boiler?
250°F.
105
What two things does a combination guage indicate?
Pressure.
Temperature.
106
The pressure available at the outlet side of a pump or circulator (expressed in feet of head) is the definition of?
Head pressure.
107
The pressure of the system under a no flow-condition. Also the pressure exerted by a column of liquid is the definition of?
Static pressure.
108
Which type of reducing couplings should be used in hydronic heating systems?
Eccentric.
109
Which valves are best suited for isolation?
Ball valve.
Gate valve.
110
Which valve is best suited for throttling-control?
Globe valve.
Needle valve.
111
What are some disadvantages of a series loop system?
Inbalanced heating.
112
What are some disadvantages of a direct return system?
Need balancing valves in all of the loops.
113
What type of valve should be used to prevent tampering with the hydronic system?
Lock shield balancing valve.
114
A piece of equipment (usually a heat exchanger type water storage) without an internal heat source.
Indirect fired.
115
Which type of circulator requires yearly maintenance?
Three piece.
116
What is the main advantage of a boiler feed valve over a PRV?
Fast-fill ability to bypass the reducing valve diaphram within the piece of equipment.
117
Referring to the figure below, what is the name of A?
Flow switch.
118
Referring to the figure below, what is the name of B?
Circulator.
119
Referring to the figure below, what is the name of C?
Auto air vent.
120
Referring to the figure below, what is the name of D?
Air scoop.
121
Referring to the figure below, what is the name of E?
Diaphram expansion tank.
122
Referring to the figure below, what is the name of F?
Boiler feed valve.
123
Referring to the figure below, what is the name of G?
Flow check.
124
Referring to the figure below, what is the name of H?
RPBA.
125
Referring to the figure below, what is the name of I?
Boiler drain.
126
Referring to the figure below, what is the name of J?
Operating aquastat / High limit aquastat.
127
Referring to the figure below, what is the name of K?
Trindicator guage.
128
Referring to the figure below, what is the name of L?
Pressure relief valve.
129
Referring to the figure below, what is the name of M?
LWCO (Probe type).
130
Referring to the figure below, what is the name of N?
Thermometer.
145
An undesirable condition during which the burner operates for a very short period of time is the defintion of?
Boiler short cycling.
146
A solution of water and glycols is the definition of?
Bryne.
147
Formation of vapor pockets when the pressure on a liquid drops below its vapor pressure is the definition of?
Cavitation.
148
A method of coupling two or more circuits so that the effect of one operating circulator does not influence the effect of another operating circulator in another circuit.
Hydraulic separation.
149
Which staging of regulators will give you more gpm?
Parallel.
150
Which staging of regulators will give you more pressure?
Series.
151
Circulation is caused in a gravity system by:
The different weight of hot to cold water.
152
The gravity circulation of water between a boiler and a heat transfer unit is called:
Convection.
153
Rough, black materials make the best:
Radiators.
154
Which system is unsuitable for heat transfer units that have a high pressure drop?
Diversion tee.
155
Which system can best balance the heat transfer between circuits of different lengths?
Reverse return.
156
Which system is a one-pipe system in which flow can be diverted to individual heat transfer units?
Diversion tee.
157
Which system is the most balanced system that uses heat transfer units?
Reverse return.
158
Which system is also known as a first fed-first return system?
Direct return.
159
A diversion tee induces flow in the branch by use of:
A venturi.
160
The series loop layout must be used with:
Forced circulation.
161
The diversion tee layout must be used with:
Forced circulation.
162
The direct return layout must be used with:
Either gravity or forced circulation.
163
Piping runs in a hot water heating system should:
Be almost level or have an upward grade of 4mm/m (1/2"/10').
164
True or false?
Piping runs should not be placed in outside walls.
True.
165
True or false?
Pump circulation can be stopped by air bubbles accumulating at a high point.
True.
166
Drops to downfeed heat transfer units should connect from the _____ of the supply pipe.
Bottom.
167
Fire-tube boilers are well suited for:
Hot water heating or steam heating.
168
Sections of a cast iron boiler are connected with:
Push nipples.
169
Boilers in hot water heating systems usually operate at:
82°C (180°F).
170
High-pressure boilers are usually made of:
Steel tube.
171
The water make-up system to the boiler is also called the:
Water supply.
172
High-efficiency boilers require:
A venting permit.
173
A convector heats the room by heating the:
Air.
174
Convectors that have fans are called:
Unit heaters.
175
A convector which does not depend on gravity for circulation uses a:
Fan.
176
Convector cabinets are usually made of:
Steel.
177
True or False?
Convectors should be installed under windows?
True.
178
The heating element of a convector is usually made of:
Finned pipe.
179
The amount of heat given off by a hot gravity circulation convector is usually regulated by an adjustable:
Louver.
180
The two types of unit heaters are:
Horizontal.
Vertical[][][]]
181
On the same circuit, do not mix convectors with:
Free-standing cast iron radiators.
182
Eccentric reducers prevent:
Air pockets.
183
What type of fitting would you use to prevent electrolysis?
Di-electric fitting,
184
Radiant panel tubing should not be installed within what distance of any gas appliance vents?
15 cm (6").
185
The minimum bend radius should be ___ times the diameter of the tube.
Ten.
186
The ideal location for a pump is immediately:
Downstream of the point of no pressure.
187
The location where the compression tank and its piping join the system piping is called:
Point of no pressure change.
188
True or false?
A strainer should be installed upstream from the pump.
True.
189
True or False?
Some circulators have water cooled and lubricated motors.
True.
190
A circulator that is oversized will:
Be noisy when it is operating.
191
Are expansion tanks used in open or closed systems?
Open systems.
192
Are compression tanks used in open or closed systems?
Closed systems.
193
A boiler fitting:
Routes air to the compression tank.
194
High points in heating systems should be:
Vented.
195
High volume locations, such as mains and unit heaters should have:
An automatic float air vent.
196
A pot feeder is not used to add:
Glycol.
197
A diverting valve diverts the:
Supply water to the return piping.
198
State the number of times water expands when it is changed to steam.
1700.
199
List three different types of steam.
Dry saturated.
Wet saturated.
Superheated[]]
200
State the location in the system where wet saturated steam can be found.
Steam space of the boiler.
201
State the location in the system where dry saturated steam can be found.
In the pipes.
202
State the type of system in which superheated steam will usually be found.
In mechanical applications.
203
State the reason superheated steam behaves like a true gas.
It has no water vapour in it.
204
State the reason dry saturated steam is used for steam heating systems.
Better at transfering latent heat.
205
State the operating pressure of most low pressure steam heating systems.
5 psi.
206
State the operating pressure used in vacuum-type systems.
Below atmospheric pressure.
207
The initials "HRT" represent:
Horizontal Return Tube Boiler.
208
Give two other names for an equalizing line.
Balancing.
Bleeder[][]
209
Explain the purpose of an equalizing line.
Returns water droplets to the boiler.
210
Collects condensate and sends back to boiler is the definition of?
Steam trap.
211
On a low-pressure steam boiler, where is a common point at which to introduce make-up water?
Condensate return pump.
212
Name the two types of expansion joints.
Slip.
Corrugated.
213
State the maximum size for a single safety valve installed on a steam boiler.
3 1/2".
214
State the maximum size safety valve that can be fitted on a steam boiler where two or more safety valves are required.
4 1/2".
215
Explain the reason for cutting off the end of the discharge pipe at a 60 Degree Angle.
Prevent build up of back pressure.
216
Difference of opening and closing pressure of the safety valve is the definition of?
Blowdown.
217
State the name given to the dial guage that records pressure above and below atmospheric pressure.
Compound guage.
218
How do you prevent steam from entering the guage?
By installing a siphon between the guage and the steam boiler.
219
State the type of valves used in the pipelines between the boiler and the water column.
O S & Y.
220
State the minimum size of piping required for the connection between the water column and the boiler.
1"
221
State the minimum size of piping required for the drain pipe from the water column.
3/4".
222
State the size of the pipe used to connect the low water cut-off with the steam boiler.
1".
223
What is the name of the piping system in which the heating transfer units are part of the piping?
Series loop.
224
What is the name of the piping system in which the heating transfer units are supplied by specialty tees?
One-pipe.
225
What is the name of the piping system in which the first heat transfer unit supplied is also the first returned?
Two-pipe direct return.
226
What is the name of the piping system in which the water has approximately the same distance to travel for each heat transfer unit?
Two-pipe reverse return.
227
What is a major disadvantage of the series loop piping system?
Limited heating capacity for each circuit.
228
What is a major disadvantage of a one-pipe system?
End heat transfer units recieve cooler water.
229
What is the major disadvantage of a two-pipe direct return piping system?
Hard to balance flow to each heat transfer unit.
230
What is the purpose of a wild loop?
To prevent the pump from deadheading.
231
What type of radiator valve should be installed to prevent unauthorized use?
Lockshield radiator valve.
232
What are the two primary considerations when locating air elimination devices?
Pressure.
Temperature.
233
Why is it important to remove gases from a hot water heating system?
To prevent air binding in the system.
234
What device removes gases directly from the boiler?
Boiler scoop.
235
What manditory device is required on a coil type boiler over 400 000 Btu/h?
Flow switch.
236
Which of the following items would indicate that you are looking at a hot water boiler and not a steam boiler?
Pressure reducing valve.
237
Which of the following items would you find on a steam boiler?
Sight glass.
238
At what temperature do fusible plugs melt?
210°F.
