Theory Level 2 Final (72-74, 90-99, 104-109)

Front 1

What are the 4 most common fuels for internal combustion engines?

Back 1

1. Natural Gas

2. Light fuels

3. Heavy fuels

4. Propane

Front 2

What are the 2 criteria for internal combustion classification?

Back 2

1. Type of fuel used

2. The type of working cycle

Front 3

What is the most environmentally friendly fuel to burn in an ICE?

Back 3

Natural gas

Front 4

Ignition of a heavy fuel in an ICE is produced by?

Back 4

High temperature caused by compression

Front 5

Governing an internal combustion engine is achieved my adjusting?

Back 5

The quantity of gas admitted

Front 6

A 4-stroke engine is equipped with what type of valves, and how many?

Back 6

Two or more poppet valves.

Front 7

How are the poppet valves held in place in a four stroke engine?

Back 7

By a spring

Front 8

What are the 2 ways a 4-stroke engine is lubricated?

Back 8

1. Splashing

2. Pumping oil in the crankcase

Front 9

What are the 2 main advantages of a 4-stroke engine?

Back 9

1. Better fuel economy

2. Better control at high speeds

Front 10

How is the fuel/gas mixture drawn into the cylinder for combustion in a 2-stroke engine?

Back 10

By vacuum from the cylinder

Front 11

How are 2-strokes lubricated?

Back 11

By mixing oil in the gas

Front 12

2-strokes cycle 2x the speed of a 4-stroke, but why don't they produce double the power?

Back 12

Because they are less efficient in cylinder scavenging

Front 13

What are the 4 sequences in a 4-stroke combustion?

Back 13

1. Suction

2. Compression

3. Power stroke

4. Exhaust

Front 14

What is the pressure and temperature of a 4-stroke compression stroke?

Back 14

540-650 degrees C and 2800-4200kPa

Front 15

What is cylinder scavenging?

Back 15

The removal of exhaust gasses in an ICE

Front 16

What is the one difficulty experiences in 2-stroke engines?

Back 16

Removal of exhaust gasses from the cylinder before the next compression stroke

Front 17

What are the most common number of cylinders in an ICE?

Back 17

4, 6, 8, and 12

Front 18

What type of ignition does diesel engines use?

Back 18

Compression Ignition

Front 19

How is gas delivered to the cylinders in a diesel engine?

Back 19

By pumps and injectors

Front 20

The moving parts in a steam engine are similar to what type of engine?

Back 20

Steam engine

Front 21

What can the compression ratio reach up to in a diesel ICE?

Back 21

25:1

Front 22

The majority of diesel engines are started using?

Back 22

Compressed air

Front 23

Briefly describe the 2 different ways the compressed air can start a diesel engine.

Back 23

1. By supplying the air to an air powered motor that will turn over the engine

2. By supplying the air to one of the cylinders

Front 24

What is the approx. pressure of compressed air that is supplied to the diesel engine for starting?

Back 24

2100kPa

Front 25

Diesel engines must be _____ before starting.

Back 25

Primed

Front 26

What must be checked on a diesel engine prior to startup? And what are you looking for?

Back 26

The valves must be checked to see if they are moving

Front 27

T/F - Only 4-stroke engines can be started using compressed air?

Back 27

False

Front 28

Improper fuel injection in a diesel engine may be due to ___ or _____ injectors.

Back 28

Worn or choked

Front 29

In some cases, incomplete combustion on a diesel engine may be due to?

Back 29

Overloading

Front 30

T/F - A diesel engine can have a HX to cool the water in the water jacket around it

Back 30

True

Front 31

Hight speed automotive diesel engines run best when the cooling water is how hot?

Back 31

Near boiling point

Front 32

What is the ideal range of temperature for a larger industrial diesel engines cooling water?

Back 32

50-60 Degrees C

Front 33

If the cooling water is too hot in a diesel engine, what can happen?

Back 33

The oil sealing properties reduce

Front 34

What happens if the cooling water is too low in a diesel ICE engine?

Back 34

The oil becomes sluggish and it prevents proper distribution

Front 35

Diesel engine governing is accomplished by?

Back 35

Governing the fuel

Front 36

How is oil kept out of the combustion chamber in an ICE?

Back 36

Piston rings

Front 37

What is the range of power requirements for pumps?

Back 37

1KW - 75,000KW

Front 38

What is the most important thing for choosing the right pump for boiler FW?

Back 38

It must be able to overcome the pressure in the boiler

Front 39

Chemical feed pumps are usually _____ units.

Back 39

Small capacity

Front 40

Why must pumps be mounted on reinforced concrete foundations?

Back 40

To provide stability and vibration control

Front 41

What is static discharge head?

Back 41

The distance from the center of the pump to the free surface of the water in the discharge tank

Front 42

That is total static head?

Back 42

The distance of supply water level to discharge water level

Front 43

What is static suction head?

Back 43

The distance from the free surface of the supply tank to the center of the pump

Front 44

What is dynamic head?

Back 44

Friction, velocity and pressure head

Front 45

What are the 3 types of pumps?

Back 45

1. Reciprocating

2. Rotary

3. Centrifugal

Front 46

In a reciprocating pump, liquid is drawn in through a?

Back 46

Suction ball check

Front 47

In a pump, if liquid is only discharges every 2 strokes it is called a?

Back 47

Single acting pump

Front 48

Centrifugal pumps convert ______ to _____.

Back 48

Centrifugal force to velocity

Front 49

What is installed in centrifugal pumps to make the conversion of energy more efficient?

Back 49

Diffuser Vanes

Front 50

What type of pump is most common for heating and chiller systems?

Back 50

Circulating pumps

Front 51

How do dynamic pumps work?

Back 51

By accelerating the water

Front 52

Is the centrifugal pump a positive displacement pump?

Back 52

No

Front 53

When head in a centrifugal pump increases, _____ will decrease?

Back 53

Capacity

Front 54

T/F - Centrifugal pumps can be ran with the valves closed

Back 54

False

Front 55

What causes cavitation?

Back 55

Vapour bubbles

Front 56

Staging pumps is used to increase?

Back 56

Differential pressure.

Front 57

A turbine pump is also called a?

Back 57

Regenerative pump

Front 58

In a turbine pump, water is circulated almost?

Back 58

360 Degrees

Front 59

A turbine pump can generate pressures almost ____ the centrifugal pump.

Back 59

Several times

Front 60

T/F - Rotary pumps are positive displacement pumps

Back 60

True

Front 61

Gear pumps are used up to what pressures?

Back 61

10,000 kPa

Front 62

What type of pump would be used to transport large amounts of fluid?

Back 62

Centrifugal pump

Front 63

Turbine pumps are best suited for?

Back 63

High pressure service

Front 64

Wear rings on a pumps are installed to?

Back 64

Reduce clearance between the shaft and improve sealing

Front 65

What is the advantage of wear rings?

Back 65

They are cheap and easy to replace

Front 66

What are wear rings usually made out of?

Back 66

Bronze and cast iron

Front 67

Wear rings are usually installed on the?

Back 67

Hub of the impeller

Front 68

What are compression pump seals usually made out of?

Back 68

Nylon, Teflon, lead or copper

Front 69

T/F - Packing in stuffing boxes is meant to completely seal water in pump

Back 69

False

Front 70

Why should there be some leakage of water in packing boxes?

Back 70

Because the water provides lubrication, and if there is not water the seals will overheat and burn up

Front 71

What is a lantern ring for?

Back 71

To provide a port for water lubrication and a stuffing box

Front 72

what are the 4 advantages of mechanical seals?

Back 72

1. Less maintenance

2. No shaft wear

3. Reduce leakage

4. They work under high temp

Front 73

What are the 2 main disadvantages of mechanical seals?

Back 73

1. More expensive

2. Pump must be taken out of service when the fail

Front 74

All mechanical sals have 2 pairs of _____ held in by ____.

Back 74

Sealing rings held in by spring & mating ring

Front 75

What are the 2 types of shaft misalignment?

Back 75

1. Angular

2. Offset

Front 76

Pump shaft misalignment causes ___ and ___.

Back 76

Overheating and excessive wear on bearings.

Front 77

What is pump priming?

Back 77

Filling the pump with water and removing the air prior to startup

Front 78

How would you prime a pump that is located above the suction tank?

Back 78

By using an external source

Front 79

Flexible couplings will compensate for?

Back 79

Axial shaft misalignment

Front 80

What are the 2 types of air compressors?

Back 80

1. Positive displacement

2. Dynamic

Front 81

Describe the concept of a positive displacement compressor

Back 81

Air is trapped, its volume is reduced and the discharges at a higher pressure

Front 82

How does the stages of compressors work?

Back 82

The # of stages is dependent on if there is more than one size of cylinder

Front 83

T/F - Sliding vane compressor has a water jacket

Back 83

True

Front 84

What is the operating speed of a sliding vane compressor?

Back 84

3000r/min

Front 85

What is the most common drive for a sliding vane compressor?

Back 85

Electric motor

Front 86

What is the least efficient compressor?

Back 86

Sliding vane

Front 87

What is the operating speed of a lobe compressor?

Back 87

1750 r/min

Front 88

How many lobes does the male and female end of the lobe compressor have?

Back 88

Male - 4 lobes

Female - 6 lobes

Front 89

In a lobe compressor, which lobe is powered by the motor?

Back 89

Male lobe

Front 90

What is the operating range for a rotary screw compressor?

Back 90

3,000-12,000 r/min

Front 91

Centrifugal compressors are used in _____ applications

Back 91

Large volume, low pressure applications

Front 92

Intercoolers decrease the?

Back 92

Amount of power to compress air

Front 93

Intercoolers may be ___ cooled or ___ cooled.

Back 93

Air cooled or water cooled

Front 94

What 3 things should be provided on a intercooler?

Back 94

1. Safety valve

2. Pressure gauge

3. Thermometer

Front 95

Instrument air must be passed through?

Back 95

Sorbents

Front 96

What does a adsorbent do to water?

Back 96

Condenses it to a thin layer of water

Front 97

When an adsorbent becomes saturated it needs to be?

Back 97

Regenerated

Front 98

What is the 2 functions of an air receiver?

Back 98

1. Store compressed air

2. Reduce pulsations from compressors

Front 99

Air filters should be installed where on compressors?

Back 99

On the inlet line

Front 100

Where should a check valve be installed on a compressed air system?

Back 100

Between the compressor and air reciever

Front 101

What are the 3 ways to control a compressor?

Back 101

1. Start/stop

2. Variable speed control

3. Constant speed motor

Front 102

External lubrication involved every moving part except the?

Back 102

Cylinder

Front 103

Internal lubrication involves the?

Back 103

Cylinder wall

Front 104

T/F - Dynamic compressors use internal lubrication

Back 104

False

Front 105

Temperatures dont become high in a compressor until?

Back 105

Maximum compression

Front 106

Before you start a compressor, ____ must be turned on.

Back 106

Cooling water for cylinder jackets

Front 107

Where are cast iron sectional boilers used?

Back 107

In small and medium steam and HW heating applications

Front 108

Cast iron sectional boilers are placed _____ and connected by ?

Back 108

Placed side-by-side and connected by tie rods and push nipples.

Front 109

How are cast iron boilers sealed?

Back 109

High temperature rope

Front 110

Each section of a cast iron boiler is placed on a rigid supporting that also contains the?

Back 110

Burners

Front 111

On a horizontal cast iron boiler, how many nipples connect sections?

Back 111

One

Front 112

On a horizontal boiler the hot gas travels in what type of pattern?

Back 112

Zig-zag pattern

Front 113

What are the 3 main advantages of cast iron boilers?

Back 113

1. Corrosion resistant

2. Easy to assemble

3. Can be placed together for more capacity

Front 114

When are heating boilers most efficient?

Back 114

When they are running at full capacity

Front 115

Modular heating boilers can be continued to create more?

Back 115

Chapters

Front 116

T/F - In modular heating boilers, flow through the chapters is continuous

Back 116

True

Front 117

T/F - Each individual chapter in modular heating boilers has its own burner and controls

Back 117

True

Front 118

The burners in the cast-iron boiler chapter are controlled by the?

Back 118

Step-controller

Front 119

Before oil can burn it must be?

Back 119

Atomized

Front 120

Why is atomization needed to burn oil?

Back 120

To increase SA of oil touching 02

Front 121

What temperature must heavy oils be heated to for burning?

Back 121

95 Degrees C

Front 122

What are the 3 types of oil burners?

Back 122

1. Air and Steam atomization

2. Mechanical

3. Centrifugal

Front 123

Air atomizing burners is usually only used one what type of heating boilers?

Back 123

Larger packaged boilers

Front 124

The air atomizing oil burner uses compressed air at what pressure ?

Back 124

100 kPa

Front 125

T/F - Air atomizing can be used on light oil or heavy heated oil?

Back 125

True

Front 126

T/F - Most industrial burners use atomizing air instead of atomizing steam

Back 126

False

Front 127

What is the size of the nozzle in mechanical oil burners?

Back 127

1mm

Front 128

In constant capacity oil burners, oil is supplied at what pressure?

Back 128

700 kPa

Front 129

Constant capacity oil burners cannot be?

Back 129

Regulated

Front 130

Constant capacity oil burners usually come as?

Back 130

A packaged unit

Front 131

Rotary cup burners spin at?

Back 131

3500rpm

Front 132

Any lift more that 4m for oil must use a ___ Pump

Back 132

Double-stage

Front 133

T/F - Double stage pumps have a return line

Back 133

True

Front 134

What type of ignitors are usually used on oil burners?

Back 134

Electric ignitors

Front 135

Electric ignitors usually require a step up transformer to step the voltage up from ____ to ____.

Back 135

240v to 10,000-12,000Dc

Front 136

Weak ignition of oil can cause a?

Back 136

Puff back

Front 137

What is a puff back?

Back 137

A puff back is when a large amount of oil explodes in the furnace

Front 138

What is the approx. oil pressure for light oils?

Back 138

550-700 kPa

Front 139

For pressure relief valves on oil burners, where does a 1 pipe system discharge oil to?

Back 139

The inlet line of the pump

Front 140

Modulating oil systems are supplied with ____ Kpa oil.

Back 140

1380kPa

Front 141

What is the minimum distance the oil tanks can be away from furnaces?

Back 141

0.6m

Front 142

Oil tanks should be how many meters away from electrical panels

Back 142

1m

Front 143

What is the highest head pressure allowed in oil tanks?

Back 143

30kPa

Front 144

how are the secondary burners lit in a multi-burner system?

Back 144

By the primary burner

Front 145

What are the 2 classifications of gas burners?

Back 145

1. Pre-mix burner

2. After-mix burner

Front 146

What is primary air?

Back 146

The air that is supplied to fuel in a burner

Front 147

What is secondary air?

Back 147

The air that is supplied in the furnace

Front 148

If the burner flame is a long pale blue flame, it is an indicator that?

Back 148

The pre-mix percentage is low

Front 149

Premix percentage in burners should be?

Back 149

30-40%

Front 150

What is the most common shape of gas burners?

Back 150

Rectangle

Front 151

Is the ring-burner a premix or after-mix burner?

Back 151

After-mix burner

Front 152

What is the main advantage of natural gas as a fuel?

Back 152

No storage space is required

Front 153

What are the 3 types of pilot burners?

Back 153

1. Continuous

2. Intermittent

3. Interrupted

Front 154

Describe the continuous pilot burner

Back 154

Pilot that stays on, even if the boiler is off

Front 155

Describe the intermittent pilot burner

Back 155

Pilot the at lights and stays on for the duration that the boiler is on

Front 156

Describe the interrupted pilot burner

Back 156

The pilot lights to light the boiler then turns off after the main flame is lit

Front 157

Automatic gas valves need what type of shutoff?

Back 157

Positive shutoff

Front 158

Solenoid valves contain what type of plunger?

Back 158

Soft iron

Front 159

T/F - large boiler burners should be supplied with full gas right away

Back 159

False

Front 160

To prevent furnace puff, oil & gas must have how long of a gradual delay?

Back 160

4-5 seconds

Front 161

A hydra-motor valve is ___ to open and __ to close.

Back 161

Quick to open and slow to close

Front 162

All pipe fittings that cannot be identified should be?

Back 162

Discarded

Front 163

What is the most common type of gauge?

Back 163

Bourdon tube gauge

Front 164

All gauges should have a ____ between the gauge and boiler.

Back 164

Pigtail

Front 165

Pressure connections on boilers should be no less than _____.

Back 165

1/4" NPS

Front 166

Boiler pressure gauge connection that are made or wrought iron should be no less than_____ in size.

Back 166

1/2"

Front 167

What is the purpose of a pigtail (syphon) on a pressure gauge?

Back 167

To have a water connection between the steam and pressure gauge to protect the gauge

Front 168

What is important when using the dead-weight tester?

Back 168

To spin the piston to ensure there is no friction

Front 169

What is the disadvantage of the hydraulic comparator gauge tester?

Back 169

Very inaccurate

Front 170

The oil in the dead-weight tester and the hydraulic comparator are?

Back 170

Medium weight oils

Front 171

What are the 2 types of valves used on the inlet and outlet of boilers?

Back 171

1. Gate valve

2. Globe valve

Front 172

What type of valve offers the least resistance?

Back 172

The gate valve

Front 173

A outside screw and yoke type valve is recommended when steam outlet is?

Back 173

51mm or bigger

Front 174

FW piping should be arranged so that?

Back 174

It doesn't directly impinge on boiler tubes

Front 175

FW piping MUST have a ______.

Back 175

Check valve

Front 176

What are the 2 type of check valves?

Back 176

1. Swing check

2. Lift check

Front 177

What is the range of sizing for blowoff piping?

Back 177

19-51mm

Front 178

What is the purpose of vent valves?

Back 178

To allow air out of the boiler when being filled and air in when drained

Front 179

A globe valve should be used in FW piping when?

Back 179

It is used to control flow

Front 180

T/F - Pressure or altitude gauges are not required on all heating boilers

Back 180

False

Front 181

The scale on altitude gauges must not be less than ___ or more that ____.

Back 181

1.5 and 3.5

Front 182

What are the 2 pointers on altitude gauges?

Back 182

1. Water height

2. Pressure

Front 183

In a system with an open expansion tank, the pressure gauge displays?

Back 183

Pressure due to hydrostatic head

Front 184

Each boiler must have a thermometer located in the boiler ______.

Back 184

Discharge

Front 185

When saftey relief valves are tested with steam the must _____.

Back 185

Pop

Front 186

How are boilers constructed to allow the boiler to drained without draining the entire water system?

Back 186

By installing stop valves on the inlet and discharge

Front 187

What temperature are open expansion tanks limited up to?

Back 187

80 Degrees C

Front 188

The air in a closed expansion tank acts as a?

Back 188

Cushion

Front 189

In a closed expansion tank, an air separator directs?

Back 189

Air into the expansion tank

Front 190

What is the first step in HW boiler startup?

Back 190

Check for a valid inspection date

Front 191

What are the 2 ok conditions that may seem wrong during startup?

Back 191

1. Light smoking

2. Condensation

Front 192

What causes light smoking in boiler startup?

Back 192

The furnace being slightly cold and not completely burning the fuels

Front 193

What causes condensation during boiler startup?

Back 193

The gold pipes are condensing the water out of the flue gasses

Front 194

Heating up a boiler too fast could cause?

Back 194

Thermal shock and uneven expansion

Front 195

Whenever going on duty what 2 things should always be checked on a HW boiler?

Back 195

Pressure and temperature

Front 196

What is the minimum temperature allowed in HW boiler? Why?

Back 196

77 Degrees C, to prevent flue gas condensation

Front 197

What percentage is the safety relief valve set at on a HW boiler?

Back 197

25% above working pressure

Front 198

The flame in HW boiler should always burn?

Back 198

Bright and evenly

Front 199

Stack temperature is a good indication of?

Back 199

Burning condition

Front 200

The maximum operating temperature in a HW boiler should never exceed?

Back 200

121 Degrees C

Front 201

How are radiators constructed?

Back 201

With large surface areas for good heat transfer

Front 202

Older versions of radiators are made out of?

Back 202

Cast iron

Front 203

What are new radiators made out of?

Back 203

Light steel welded together

Front 204

What is a unit heater?

Back 204

A convector with a blower of fan

Front 205

What are the 3 components that are integrated un a unit ventilator (univent)?

Back 205

1. Air filters

2. Dampers

3. OA inlets

Front 206

How did old steam heating systems remove air from the system?

Back 206

Petcocks

Front 207

Radiator traps allow?

Back 207

Condensate to escape from the radiator but not steam

Front 208

Vacuum pumps help?

Back 208

Condensate removal

Front 209

The exhauster is a?

Back 209

Series of nozzles

Front 210

What are horizontal pipes called in steam heating systems?

Back 210

Mains

Front 211

What are vertical pipes called in steam heating systems?

Back 211

Risers

Front 212

What is a wet return?

Back 212

When the main is below the water line in the boiler

Front 213

Describe a one-pipe system in steam heating.

Back 213

There is one pipe for the steam and condensate

Front 214

What is the pressure range for a 2-pipe gravity return system?

Back 214

0-130kPa

Front 215

What is important in a gravity steam heating system?

Back 215

The boiler must be located below the radiator

Front 216

A brand new steam heating system should first be?

Back 216

Started up by the contractor

Front 217

Air vents on steam heating systems should be cleaned?

Back 217

Regularly

Front 218

What is common practice in steam heating systems?

Back 218

To perform an overhaul every summer

Front 219

A pressure balancing device that prevents boiler pressure from forcing water into the return line is called?

Back 219

Hartford loop

Front 220

A vacuum pump maintains a vacuum of ____ higher in the condensate system.

Back 220

7-10 kPa

Front 221

What is the maximum temperature allowed in a gravity HW heating system?

Back 221

77 Degrees C

Front 222

What is the 2 most common pressures in a hydronic heating system?

Back 222

85 and 140 kPa

Front 223

What is the cheapest HW heating pipe configuration?

Back 223

Series loop

Front 224

What is the disadvantages of the series loop and the one pipe HW heating layouts?

Back 224

Water gets cooler and it travels through the building.

Front 225

2-pipe direct HW system is also called?

Back 225

First fed, first returned

Front 226

The difference between the 2-pipe direct system, and the 2-pipe reverse return system is that?

Back 226

The 2-pipe reverse return, return water makes a full loop before returning to the boiler.

Front 227

T/F - in a multi-zone HW heating layout, each zone has its own pump

Back 227

True

Front 228

T/F - A single circulator is used for a multi-zone heating system

Back 228

True

Front 229

What are the 3 advantages of HW systems over steam?

Back 229

1. HW boiler is smaller and more compact

2. Piping pitch is less critical

3. Less maintenance cost

Front 230

Snow melting coils should be placed at least ____ under the concrete?

Back 230

5cm

Front 231

The max temperature in radiant heating panels is about?

Back 231

80 Degrees C

Front 232

Diverter fittings were used in?

Back 232

1-pipe systems to divert water from the main to each convector

Front 233

Why is it important to vent HW systems during startup?

Back 233

Because cold water contains more air

Front 234

Air separators can be described as?

Back 234

Air scoops in pipes.

Front 235

What is a more common air separator in HW systems, and how does it work?

Back 235

The Aristotle separator, its a fitting on the boiler that has a pipe that raws water from more deep in the water line so less water is obtained.

Front 236

What is installed to prevent occupants from contaminated water?

Back 236

Back flow preventer

Front 237

What is the minimum pressure at the highest point in a HW heating system?

Back 237

12 kPa

Front 238

FW for heating boilers is usually controlled by a?

Back 238

Float

Front 239

The float housing in a HW boiler also usually houses the?

Back 239

Low water cutout

Front 240

ASME states that the low water cutout must cut off the boiler before?

Back 240

The water level drops below the visible point on the gauge glass

Front 241

What are the 2 ways HW boilers are filled with water?

Back 241

1. Electric feeder valve

2. Float operated mechanical feeder valve

Front 242

What are the 2 ways HW boilers are supplied with water?

Back 242

1. Hartford loop

2. FW pumps

Front 243

Why are Hartford loops installed on HW boiler FW systems?

Back 243

In case the check valve fails

Front 244

T/F - the amount of HW leaving the boiler should be the same amount of condensate returning

Back 244

True

Front 245

T/F - If multiple boilers are used in a plant, each individual boiler has its own feed water control.

Back 245

True

Front 246

How is the size of condensate receiver determined?

Back 246

by the amount of water evaporated in 1/2 an hour

Front 247

What are the 2 HW boiler FW impurities?

Back 247

1. o2

2. co2

Front 248

What are the 3 types of HW boiler combustion controls?

Back 248

1. On/Off

2. High/low

3. Modulating

Front 249

What is the most inefficient way to control a HW heating boiler?

Back 249

ON/Off control

Front 250

What is the purpose of a differential spring in a on/off HW boiler control?

Back 250

Increases shutoff range for boiler

Front 251

What is the high/low switch for in HW boiler combustion control?

Back 251

Large demand control

Front 252

In a modulating burner control, what controls the burner?

Back 252

The change in resistance on the controller

Front 253

What is the difference in steam boiler controls from HW boiler controls?

Back 253

HW controls have expanding elements

Front 254

Boilers with high/low or a modulating burner must have a?

Back 254

Damper

Front 255

What are the 3 safety switches on a HW boiler?

Back 255

1. Low air

2. Low gas

3. High gas

Front 256

What type of burners are required for high-low fire control?

Back 256

Multiple burners

Front 257

What are the 3 types of flame detectors?

Back 257

1. Flame rod

2. Thermocouple

3. Photoelectric cell

Front 258

What type of flame scanner is used for a pilot burner?

Back 258

Thermocouple

Front 259

Voltage supplied from a thermocouple is usually no more than?

Back 259

30mV

Front 260

Thermocouples in series are called?

Back 260

Thermopiles

Front 261

The flame rod acts like an?

Back 261

Electrical circuit

Front 262

The infrared cell contains what type of material?

Back 262

Lead-sulphide

Front 263

In an infrared scanner, as infrared light increases, resistance?

Back 263

Decreases

Front 264

What is the maximum temperature for a ultraviolet light?

Back 264

10 Degrees C

Front 265

The maximum temperature for a lead-sulphide cell is?

Back 265

50 Degrees C

Front 266

What is the pressure range that is supplied to a pneumatic storage tank?

Back 266

480-550 kPa

Front 267

The sensing element in a pneumatic controller measures the?

Back 267

Change in temperature, humidity and pressure in space

Front 268

When a controller increases its output with an increase in system condition it is called?

Back 268

Direct acting

Front 269

Bi-metal elements are usually found in?

Back 269

Bleed type thermostats

Front 270

What is the purpose of an interval valve on a non-bleed?

Back 270

To seat the supply port valve

Front 271

What are the 3 types of sensing elements in a humidistat?

Back 271

1. Human hair

2. Membrane

3. Bi-wood

Front 272

What are the 2 types of dampers?

Back 272

1. Parallel Blade

2. Opposed Blade

Front 273

If you were looking for a quick opening damper blade, what configuration would you use?

Back 273

Parallel blade

Front 274

What is the purpose of a pilot positioner?

Back 274

To sense the position of a damper or valve

Front 275

Operation of a self-contained control system is dependent on?

Back 275

Change in air temperature

Front 276

The most common damper operator is the?

Back 276

Piston type

Front 277

What are the 2 voltages used for electric controls?

Back 277

120v or 240v

Front 278

What is the temperature range for bi-metal coil thermostats?

Back 278

10-32 Degrees C

Front 279

Modulating thermostats contain a ?

Back 279

Potentiometer

Front 280

Thermostats should always be at least ____ above the floor?

Back 280

1.5m

Front 281

The sensing element in a humidistat is called an?

Back 281

Hygroscopic element

Front 282

The most common motor used for valve control id the?

Back 282

Capacitor type

Front 283

In a capacitor motor, the housing is usually filled with?

Back 283

Oil

Front 284

Electronic systems use low v___ and _____.

Back 284

Voltages and currents

Front 285

What is deviation?

Back 285

The difference between the SP and PV

Front 286

What are the 2 types of electronic sensors?

Back 286

1. Digital

2. Analog

Front 287

What is an RTD?

Back 287

Resistance temperature device

Front 288

What is BALCO constructed of?

Back 288

70% nickel and 30% iron

Front 289

What is the temperature ranges for BALCO?

Back 289

-40 to -120 Degrees C

Front 290

What is another metal used in RTD's besides BALCO?

Back 290

Platinum

Front 291

Do thermistors have a positive or negative temperature coefficient?

Back 291

Negative

Front 292

T/F - Thermistors are quickly responsive

Back 292

True

Front 293

As temperature increases in a thermistor, resistance will go?

Back 293

Down

Front 294

Thermocouples have 2 dissimilar metals such as?

Back 294

Iron and Constantan

Front 295

An advantage of electronic controllers is that?

Back 295

It can accept a wide variety of inputs

Front 296

An electronic controller is used to position a?

Back 296

Actuator

Front 297

What are the 3 metals used in RTD's?

Back 297

1. Iron

2. Nickel

3. Platinum

Front 298

Electric to pneumatic transducers convert modulating 2-10 DC to what kPa

Back 298

0-90 kPa

Front 299

An electric pressure sensor consists of a ___ that converts pressure changes to different variables.

Back 299

Transmitter

Front 300

F-U-C-K

Back 300

S-C-H-O-O-L