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EPA > Monday Test > Flashcards

Monday Test Flashcards

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1
Q

How can ice be removed from a sight glass

A

with alcohol spray

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2
Q

What must be done with badly corroded relief valves

A

replace them

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3
Q

Where can you find the allowable test pressure on a system

A

Unit Data Plate

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4
Q

Can Oxygen be used to check for leaks? If not why not?

A

No. Oxygen in the presence of oil under high pressure can be explosive

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5
Q

What is the likely result of heating a recovery cylinder with an open flame

A

The refrigerant inside will decompose into a toxic material, venting of refrigerant into the atmosphere or the tank may explore

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6
Q

What is the primary purpose of disposable cylinders?

A

For virgin refrigerants from the manufacturer

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7
Q

To what internal pressure should a disposable cylinder be reduced to for disposal?

A

0 PSIG

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8
Q

Should you ever use a disposable cylinder for refrigerant recovery

A

No

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9
Q

To dispose of a cylinder you should be sure all refrigerant is recovered and the cylinder is no longer usable. What else?

A

Puncture the container before disposal

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10
Q

For safety, refrigerant cylinders should not be rusted or damaged and always properly color coded. What additional step should also be taken with these cylinders?

A

Properly secured at all times

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11
Q

What is the proper color code for recovery cylinders?

A

Grey with a yellow top

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12
Q

What is the maximum percent by weight that a cylinder may be filled

A

80%

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13
Q

What can happen if a cylinder is overfilled

A

Hydrostatic pressure could cause the cylinder to explode

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14
Q

List 3 methods for measuring the fill level of a recovery cylinder?

A

Floats, thermistor type sensors, weighting scales

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15
Q

How often must reusable cylinder be hydrostatically tested?

A

every 5 years

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16
Q

Why must only refillable cylinders be used for transport

A

Federal code of regulations title 49

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17
Q

The clean air act phases out CFC/HCFC production and prohibits venting. What else does it require

A

Standards to be set for recovery of all refrigerants prior to appliance service and disposal

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18
Q

Falsifying or failing to keep required records, failing to reach required evacuation levels and knowinly releasing CFC or HCFC refrigerants are violations of the Clean Air Act. What activity with a substitute refrigerant is also a violation?

A

KNOWINGLY venting CFC and HCFC and their substances.

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19
Q

Which refrigerants must be recovered prior to opening a system?

A

All refrigerants as of November 15 1995

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20
Q

What releases of a CFC and HCFC are violations of the Clean Air Act?

A

Any KNOWINGLY vented refrigerants

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21
Q

On what date did it become illegal to vent CFC and HCFC

A

July 1 1992

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22
Q

Which appliances are covered by Section 608

A

Any device which contains and uses a class 1 or class 2 substances as a refrigerants and is used for household or commercial purposes.

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23
Q

What is the primary reason the EPA requires a service aperture or process stuff on all appliances

A

For adding or removing refrigerant from the appliance

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24
Q

The Montreal Protocol calls for the regulation of what chemicals

A

Ozone depleting compounds CFC HCFC and Halons

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25
Q

On what date was the importation and production of all CFC phased out?

A

In the US December 31 1995

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26
Q

Where will we get replacements?

A

Through recovery of existing refrigerants

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27
Q

What steps are called for by the Clean Air Act

A

Taxes on production and use, standards set for the recovery of refrigerants

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28
Q

What is prohibited by the Clean Air Act

A

Venting

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29
Q

Does Atmospheric Ozone help or hurt the work of the earths protective shield

A

It helps

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30
Q

What chemical in the statosphere tells us ozone depletion is occurring?

A

Chlorine-monoxide

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31
Q

How do we know the chlorine in the statosphere is coming from CFC?

A

the increase in chlorine and flourine matches the emmissions of CFC

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32
Q

How do we know CFC get to the statosphere

A

from high altitude air sampling measurements

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33
Q

What role does the ozone layer play in protecting the earth?

A

it blocks much of the harmful ultraviolet radiation UV-B

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34
Q

What are the effects from increase UV radiation

A

Skin cancer, cataracts, lowered human immunity

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35
Q

What are the effects of increased UV radiation on the environment?

A

timber growth is reduced, crop yields lowered, marine life and food chain are impaired.

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36
Q

What is the Montreal Protocol

A

A treaty that called for the reduction of production of CFCs

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37
Q

What is a ternary blend?

A

a blend of 3 different refrigerants

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38
Q

How should systems using blended refrigerants be charged?

A

in liquid for into the high side of the system

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39
Q

in there a drop in refrigerants for CFC-12

A

No

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40
Q

How do you leak check HFC134a system with a partial charge

A

recover the remaining refrigerant and pressurize with nitrogen add r22 so you can use a HCFC leak detector

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41
Q

What is the preferred oil to be used with HFC-134a

A

Ployolester

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42
Q

Can ester based oils be mixed with other oils

A

No

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43
Q

What lubricant is recommended for use with a ternary blend?

A

For HCFC Alkylbenze for HFC Ployolester or ester oil

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44
Q

Safety and butyl lined glves should be worn for what procedure

A

When operating recovery or recycling devices and when handling and refilling refrigerants cylinder

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45
Q

What is HFC

A

A fluorocarcon that contains no chlorine

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46
Q

Which refrigerants are HFC’s

A

R134a. 404a, 407C, 410a

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47
Q

What is the ODP of HFC

A

Zero

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48
Q

Which refrigerant have high ODP

A

CFC

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49
Q

Which refrigerants have low ODP

A

HFCF and HFC

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50
Q

Does R500 have a CFC

A

Yes

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51
Q

What precautions should be taken when recovering refrigerant from a system with multiple service valves

A

Insure that liquid is not trapped between service valves

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52
Q

What is different about any leaks in systems charged with a blended refrigerant?

A

Because they are blended the ingredients will leak at different rates

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53
Q

What purpose is served by heating a system during evacuation

A

to speed up moisture removal

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54
Q

What is the result of over evacuating a system

A

no damage will be done

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55
Q

When measuring the vacuum of a system being evacuated the system must be isolated. What must be done to the vacuum pump?

A

Valve it off and turn it off

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56
Q

How much ozone can chlorine atom destroy

A

100,000

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57
Q

What refrigerants are CFCs

A

R11,12,113,114

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58
Q

What refrigerants are HCFC

A

R22 R123

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59
Q

What is a material safety data sheet

A

a sheet that states the safety ratings and precautions to be taken for use and handling of chemicals

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60
Q

What safety classification within the ASHRAE standard is most safe

A

A1

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61
Q

What is caused by inhaling of refrigerant vapors

A

heart irregularities or Asphyxia

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62
Q

What is the major cause of death involving refrigerants

A

Oxygen deprivation

63
Q

What breathing problems can be caused by CFC12

A

Asphyxia

64
Q

What is the preferred instrument for detecting small leaks

A

Electronic leak detector and Ultrasonic detector

65
Q

When may a technician recover only 80% of the refrigerant in a small appliance?

A

In a system dependent recovery with a non operating compressor?

66
Q

May a technician use a passive recovery machine for recovery from a domestic refrigerator?

A

Yes

67
Q

What requirements are placed on recovery machines built after November 15 1993?

A

Must be able to recover 80% if compressor is inoperative or 90% if its working and must be EPA certified

68
Q

When using a recovery machine made after November 15 1993 what percentage of the refrigerant must be recovered in a household refrigerator with and without an operational compressor

A

90%/80%

69
Q

What must be affixed to a refrigerant cylinder prior to its shipment to a reclaimer?

A

DOT classification tag

70
Q

What is the purpose of a DOT classification tag

A

its for transportation purposes

71
Q

What is the EPA definition of a small appliance

A

charged at factory with 5lbs of refrigerant or less

72
Q

Is it required to repair leaks in a small appliance?

A

No but recommended

73
Q

What service aperture may be used on a small appliance

A

access tubes or process tubes

74
Q

On what material are piercing valves used?

A

copper and aluminum lines

75
Q

What should be done to a schrader valve after it is installed on a charged system?

A

capped off after any service procedure

76
Q

Why should solder-less type piercing valves be removed after completion of repairs?

A

to prevent leaks

77
Q

What are the critical maintenance checks done to a schrader valve

A

periodically checked for leaks and replaced if damaged

78
Q

What do you do if oil is contaminated

A

tubing flushing

79
Q

Why do large refrigerant leaks cause suffocation?

A

refrigerant will replace air in the confined space leading to possible oxygen starvation

80
Q

How should you access the system and should you run the compressor when using a system dependent (passive) recovery on a refrigerator with an operable compressor

A

access the high side and run the compressor

81
Q

What is the purpose of a compressor heater

A

to reduce the amount of refrigerant in the lubricating oil

82
Q

What is the preffered method of leak checking a built up system prior to charging?

A

bubble solution

83
Q

Who sets the regulations for recovery machines?

A

EPA

84
Q

What is a self contained recovery machines

A

A recovery machine that has its own compressor to pump refrigerant out of the system

85
Q

HCFC123a is a

A

low pressure refrigerant

86
Q

CFC12

A

high pressure refrigerant

87
Q

What are the typical ranges of pressure in a manifold

A

0-500 on high side and 0-350 low side and 0-30hg

88
Q

According to ASHRAE Standards 15 what is the standard for refrigerant concentration for a machine room that must not be exceeded without activating an alarm and starting ventilation in the machine room

A

TLV TWA

89
Q

List 4 safety procedures that should be followed when working with liquid low pressure refrigerant

A

Refrigerant sensor, avoid siphoning refrigerant by mouth, wear butyl lined gloves and safety glasses

90
Q

what is the toxicity and flammability rating of HCFC-123 per ASHREA standard 34

A

B1

91
Q

Device to prevent venting and loss in REFRG

A

Low loss fitting (Shut off valve)

92
Q

What is the primary purpose of using hand valves or self sealing hoses hen using a gauge set

A

to prevent loss of refrigeration

93
Q

Which refrigerants must be recovered according to 608 EPA

A

CFC, HCFC, HFC

94
Q

The replacement refrigerant NOT DROP IN for CFC-12 in household refrigerators is

A

HFC-134a

95
Q

When doing a non condensables check, a recovery cylinder should stabilize in temperature before any readings are taken why?

A

to find the correct pressure for that temperature on a T/P Chart

96
Q

What is a system dependent recovery machine

A

One that relies on the compressor of the system being serviced or the pressure of the refrigerant to pump the refrigerant into the recovery drum

97
Q

Describe a system dependant passive recovery process for small appliances

A

evacuate and cool recovery cylinder and connect to high and low side and use low pressure or a vacuum on tank

98
Q

What 2 conditions require that you access both high and low side of the system for refrigerant recovery

A

when compressor is broken or you need to adjust required recovery levels

99
Q

What is the initial charging method of a system when the charge is specified at 70lbs

A

charged in liquid state

100
Q

Where is the accumulator located in a refrigeration system

A

on the suction line before the compressor

101
Q

To prevent freezing of any moisture in a CFC-12 system vapor should first be charged to what level

A

33psig

102
Q

What leak rates is permissible on industrial and process refrigeration

A

as of June 14 1993 a leak rate of 35% or more on equipment with 50lbs or charge or more must be repaired. Less than 35 is allowed

103
Q

What leak rates is ok on equipment other than industrial or process equipment that contains more than 50lbs of refrigerant

A

Less than 15% a year

104
Q

Why must water be circulated through a chiller during refrigeration recovery

A

To prevent freezeup of the water as pressure is reduced on the refrigerant

105
Q

What is the lowest access valve on a low pressure chiller

A

The evaporator charging valve

106
Q

Where is a centrifugal chiller rupture disk attached

A

at the evaporator

107
Q

What is the typical pressure setting for a low pressure chiller rupture disk

A

15 PSIG

108
Q

How is a chiller typically charged

A

Liquid through the evaporator charging valve

109
Q

What minimum saturation temperature needs to be achieved before liquid is charged into a chiller

A

Above freezing typically 36f

110
Q

To prevent freezing of water when charging a chiller, what pressure should be reached with vapor before using a liquid CFC-11

A

16.9 inches of Mercury

111
Q

What could result from liquid refrigerant being charged into a chiller that is holding a 29.9 Inches of Mercury vacuum

A

Can cause system water to freeze

112
Q

What function is served by a purge unit on a chiller

A

to reduce the effects of contamination and to purge non condensables.

113
Q

What is the most likely cause of air leaks into a chiller refrigerated circuit

A

Gaskets and fittings

114
Q

How is a purge unit connected on a low pressure chiller

A

the inlet of the purge unit is typically connected to the top of the condenser

115
Q

Where is the suction of a purge unit connected

A

the inlet of the purge unit is typically connected to the top of the condenser

116
Q

What is a high effeciency purge unit

A

it removes non-condensables that contain low percentages of refrigerant. This adds to the valve of the purge drum in refrigerant containment

117
Q

Shaft seals on an open type compressor are susceptible to what failures

A

refrigerant leaks

118
Q

What rise in a vacuum is permitted under ASHRAE 3-1990

A

after 12 hours no more than 2.5mm of Mercury

119
Q

List two steps to reduce the run time of a purge unit on a chiller

A

regular leak checks and repair any leaks

120
Q

Why should the water side of the evaporator and condenser be drained before recovering refrigerant from a chiller suspected of having a tube leak

A

to prevent moisture from being drawn into the refrigerant circuit

121
Q

If a purge unit is operating excessively it usually will mean?

A

Leaks

122
Q

What condition would cause continuous excessive moisture collection in the purge unit of a low pressure refrigeration system?

A

Leaks between the refrigerant circuit and the water circuit

123
Q

Why would oil be warmed prior to removal from a low pressure chiller

A

to vaporize any liquid refrigerant that might be trapped in the oil

124
Q

Is recovery of a refrigerant from a low pressure appliance typically started with liquid or vapor

A

Liquid removal

125
Q

Purge unit work best when they are not needed. How can purge unit operating time be reduced

A

regular leak checks and repair on a regular schedule

126
Q

Max pressure for leak checking a low pressure chiller

A

10PSIG on low pressure equipment that uses rupture disk

127
Q

What is the preffered method of leak checking a chraged low pressure chiller?

A

by increasing the refrigerant pressure using an external heat source or running hot water through the chiller tubes not to exceed 10 PSIG

128
Q

Where would you check for leaks between a chiller refrigerant tube and the water box

A

the chiller barrel can be emptied of all water and a leak check made at drain valve with water off. If tubes require leak check the check can be made with a hydrostatic tube test kit

129
Q

What is a hydrostatic tube test kit used for

A

to check for leaks in a chiller tubes

130
Q

What leaks rate is ok on industrial and process refrigeration

A

35% or more fix less than 35 is cool

131
Q

Before using a recovery unit the tech should check service valve position and check the recovery unit oil level. What additional steps must be taken

A

All selenoid valves should be open

132
Q

What can cause recovery equipment with a hermetic compressor to overheat when drawing a deep vacuum

A

no airflow over the compressor body or no suction gas flow over internal motors or both

133
Q

What is the reason for not operating a hermetic compressor while in a deep vacuum

A

to prevent overheating

134
Q

What is the reason for not starting a reciprocating compressor with its discharge service valve closed

A

prevent overheating

135
Q

When can a “system dependent” recovery device be used

A

on small appliance as long as the recovery device meets EPA standards and the tech adheres to the servicing procedures specified for the recovery equipment. Cannot be used on a system with more than 15lbs refrigerant charge

136
Q

What vacuum level must you reach when recovering from a system with 38 pounds of R502 using a recovery machine made in 1995

A

10 inches of Hg

137
Q

In order to recover from a system with parallel compressors the individual compressors must be isolated why

A

it isolates the refrigerant that must be recovered from the rest of the system

138
Q

Which refrigerants require an equipment monitor

A

all refrigerants

139
Q

How should you pressurize an idle low pressure chiller to prevent air accumulation

A

Slightly above atmospheric pressure

140
Q

Prior to making a major repair what vacuum level must you pull when using recovery equipment made in 1996 on a unit with 215lbs of CFC-12

A

15 inches of mercury

141
Q

Under what circumstances may a tech recover the CFC refrigerant in an appliance to atmostpheric pressure only

A

leak or if it would contaminate the refrigerant

142
Q

What is the water source for a condensing coil on a water cooled recovery machine

A

Municipal water tap

143
Q

Where is the connection made for the water supply used on a water cooled recovery unit

A

local water supply

144
Q

What should be the max pressure on the discharge of a recovery machine for low press systems

A

10psig since rupture disk bust at 15

145
Q

What should be done with the water pumps during a recovery from a low pressure chiller

A

turn the water pump on

146
Q

what recovery vacuum meet for appliance made in 1992

A

25Hg

147
Q

To ship recovered refrigerant you must label the container and complete all necessary paperwork. What else

A

Send it in a DOT approved cylinder

148
Q

What are piercings valves used for

A

to allow access to the sealed system for recovery

149
Q

What does backseating a valve mean

A

allows flow through the main line while closing the access point

150
Q

What will non condensables do to the pressure in refrigerant circuit

A

increase discharge pressure

151
Q

Where is a receiver typically installed on a system

A

At the outlet of the condenser

152
Q

Before enter an area of a large leak of refrigerant what apparatus must be worn

A

self contained breathing aparatus

153
Q

What should be done if a large leak occurs and no breathing apparatus avail

A

ventilate and leave

EPA (1 decks)

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