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EPA 608 Type II study materials
EPA 608 Type II study resources

EPA 608 Type II practice questions

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Question 1Leak Detection

Which leak detection method pinpoints a leak by coating joints and fittings with a solution and watching for bubbles?

  1. Fluorescent dye additive
  2. Soap bubble solution Correct answer.
  3. Electronic leak detector
  4. Ultrasonic leak detector

Explanation

The bubble test uses a surfactant solution brushed onto joints, and escaping gas forms visible bubbles at the leak point. It is reliable for confirming and pinpointing a leak once the general area is known. It works only on systems that are under positive pressure.

Question 2Leak Detection

Which gas should be used to pressurize a refrigeration system for a leak test?

  1. Oxygen
  2. Compressed air
  3. Dry nitrogen Correct answer.
  4. Acetylene

Explanation

Dry nitrogen is inert, oil-free, and does not react with refrigerant or compressor oil, so it is the accepted pressurizing gas for leak testing. It is supplied through a pressure regulator so the system is not over-pressurized. Nitrogen also leaves no moisture behind.

Question 3Leak Detection

Why is oxygen never used to pressurize a refrigeration system for leak testing?

  1. It is not available in cylinders large enough for field use
  2. It leaves a corrosive residue inside the piping
  3. It is too costly to use on large systems
  4. It can ignite or explode when it contacts compressor oil Correct answer.

Explanation

Oxygen under pressure mixed with refrigerant oil creates an explosive condition, and any ignition source can cause a violent reaction. Only dry nitrogen is acceptable for pressure testing. The hazard exists even at moderate test pressures.

Question 4Leak Detection

Before using an electronic leak detector, a technician should confirm that the instrument is:

  1. Certified for flammable refrigerants only
  2. Set to the highest sensitivity setting
  3. Calibrated for the refrigerant in use Correct answer.
  4. Equipped with a heated sensing element

Explanation

Detectors are refrigerant-specific, and a unit calibrated for one refrigerant may be insensitive to another. The technician verifies calibration and sensitivity in a clean-air location before testing. Accurate calibration is what makes a negative test meaningful.

Question 5Leak Detection

A system is evacuated, the pump is valved off, and the vacuum level rises over the next hour. What does this indicate?

  1. The vacuum pump is oversized for the system
  2. The system has been fully evacuated
  3. The system has a leak or contains moisture Correct answer.
  4. The refrigerant charge is correct

Explanation

A standing vacuum test measures whether the system holds a vacuum after the pump is isolated. A rising micron level means air is entering through a leak or that moisture is boiling off inside the system. A tight, dry system holds its vacuum level.

Question 6Leak Detection

Which instrument locates a leak by detecting the sound produced by refrigerant escaping from an opening?

  1. Halide torch
  2. Ultrasonic leak detector Correct answer.
  3. Vacuum pump
  4. Micron gauge

Explanation

Ultrasonic detectors use a directional microphone and headphones to sense the high-frequency turbulence of gas escaping through a small opening. They are useful when an electronic detector is affected by background contamination. They do not respond to refrigerant chemistry.

Question 7Leak Detection

When using an electronic leak detector to check a braze joint, the probe should be moved:

  1. Only after the system is pulled into a deep vacuum
  2. At least six inches away from all fittings
  3. Rapidly around the joint to cover more area
  4. Slowly and close to the surface being tested Correct answer.

Explanation

The sensor needs time to draw in a sample, so the probe is moved about one inch per second and held within a fraction of an inch of the surface. Moving too quickly or holding the probe too far away lets refrigerant escape detection. Testing is done with the system under pressure, not under vacuum.

Question 8Leak Detection

HFC refrigerants are heavier than air, so a technician checking for leaks places the detector probe:

  1. At the highest point of the system
  2. Below the suspected leak point Correct answer.
  3. Only at the compressor discharge
  4. Near the vacuum pump exhaust

Explanation

Because HFC vapor is denser than air, it settles downward after escaping, so sampling below a joint improves pickup. The probe is still passed directly over the joint, since the leak is at the surface. This practice shortens the time needed to find a leak in open areas.

Question 9Leak Detection

A commercial refrigeration appliance with a 100-pound charge has had 25 pounds of refrigerant added over the past 12 months. What is the leak rate?

  1. 12.5 percent
  2. 25 percent Correct answer.
  3. 2.5 percent
  4. 40 percent

Explanation

The annual leak rate is the refrigerant added over 12 months divided by the appliance's full charge, times 100. Here 25 divided by 100 equals 25 percent. This figure is then compared with the applicable threshold for the appliance type.

Question 10Leak Detection

Which leak rate threshold applies to a comfort cooling appliance under the leak repair requirements?

  1. 10 percent Correct answer.
  2. 20 percent
  3. 5 percent
  4. 35 percent

Explanation

Comfort cooling appliances have a lower leak rate threshold than commercial refrigeration because of their typical charge sizes and usage patterns. Exceeding it triggers the repair, verification, and recordkeeping requirements. Commercial refrigeration appliances use a 20 percent threshold.

Question 11Leak Detection

A 60-pound commercial refrigeration appliance is found to exceed the applicable leak rate. Absent an extension, the repair must be completed within:

  1. 14 days
  2. 30 days Correct answer.
  3. 7 days
  4. 90 days

Explanation

When an appliance above the charge threshold exceeds its leak rate, the owner must repair the leak within 30 days of discovery. If repair is not feasible, the owner must instead retrofit or retire the appliance. Documentation of the repair must be retained.

Question 12Leak Detection

After a leak is repaired on an appliance that exceeded the leak rate threshold, the initial verification test must be performed no later than:

  1. 14 days after the repair
  2. 7 days after the repair
  3. 24 hours after the repair
  4. 30 days after the repair Correct answer.

Explanation

The initial verification test is conducted as soon as practicable after the repair and must be completed within 30 days. It confirms that the repair actually sealed the leak before the appliance returns to normal leak-rate tracking. A follow-up verification test is also required afterward.

Question 13Leak Detection

Which technique adds a small amount of the appliance's own refrigerant to nitrogen so that an electronic detector can be used during a pressure test?

  1. Nitrogen sweep
  2. Deep vacuum decay test
  3. Standing vacuum test
  4. Trace gas method Correct answer.

Explanation

With the trace gas method, a small quantity of the system refrigerant is blended with dry nitrogen to raise the pressure. The electronic detector then responds to the trace refrigerant as it escapes. This keeps the amount of refrigerant used small while still enabling sensitive detection.

Question 14Leak Detection

A technician is leak testing the low side of a system that has been isolated from the high side. The test pressure must not exceed:

  1. The low-side design pressure Correct answer.
  2. The full nitrogen cylinder pressure
  3. The high-side design pressure
  4. The maximum gauge manifold rating

Explanation

With the low side isolated, the high-side valve and components are protected only by the low-side components, so test pressure is limited to the low-side design pressure. Exceeding it can rupture the evaporator or other low-side parts. A pressure regulator is used to control the nitrogen.

Question 15Leak Detection

Which practice is prohibited when leak testing a refrigeration system?

  1. Pressurizing with refrigerant alone Correct answer.
  2. Pressurizing with dry nitrogen
  3. Applying soap bubbles to the joints
  4. Using an electronic leak detector

Explanation

Refrigerant may not be used as the sole pressurizing gas because the charge would have to be vented afterward, and intentional venting is prohibited. Dry nitrogen, sometimes with a trace of refrigerant, is the accepted approach. Refrigerant must be recovered, not released.

Question 16Leak Detection

An appliance contains 40 pounds of HFC-134a. Which statement about leak repair requirements is correct?

  1. Repair is required within 7 days of discovery
  2. Repair is required whenever any leak is found
  3. Repair is required only above 35 percent
  4. Mandatory leak repair rules do not apply Correct answer.

Explanation

The appliance leak repair requirements apply to appliances containing 50 or more pounds of refrigerant. A 40-pound charge falls below that threshold, so the repair deadlines and leak-rate calculations do not apply. The venting prohibition and safe handling practices still apply.

Question 17Leak Detection

Fluorescent dye is added to a refrigeration system in order to:

  1. Show leaks under ultraviolet light Correct answer.
  2. Permanently seal small leaks
  3. Raise system pressure during testing
  4. Absorb moisture from the system

Explanation

Dye circulates with the lubricant and escapes at the leak, leaving a fluorescent stain that is visible under a UV lamp. It is used in conjunction with the repair of the leak, not instead of it. The dye must be compatible with the refrigerant and oil in the system.

Question 18Leak Detection

With the system isolated and its temperature stable, a nitrogen pressure test drops from 150 psig to 120 psig in one hour. This indicates that:

  1. The nitrogen cylinder has emptied
  2. The system is properly sealed
  3. The gauge manifold is reading incorrectly
  4. The system has a leak Correct answer.

Explanation

In an isolated system at constant temperature, a sustained pressure loss means gas is escaping. The rate of loss can help estimate the size of the leak. Temperature changes must be ruled out because they also change pressure.

Question 19Leak Detection

An appliance with a 75-pound charge had 8 pounds of refrigerant added in March and 10 pounds added in September. What is the leak rate for the 12-month period?

  1. 10.7 percent
  2. 18 percent
  3. 12 percent
  4. 24 percent Correct answer.

Explanation

All refrigerant added during the 12-month period is totaled, then divided by the full charge: 18 divided by 75 equals 24 percent. Each addition counts, not just the most recent one. The total is then compared with the threshold for the appliance type.

Question 20Leak Detection

A 200-pound comfort cooling appliance had 15 pounds added over 12 months, and a 60-pound commercial refrigeration appliance had 14 pounds added over 12 months. Which appliance requires repair?

  1. Both of them
  2. Only the comfort cooling one
  3. Neither of them
  4. Only the commercial one Correct answer.

Explanation

The comfort cooling appliance leaked 7.5 percent, which is below its 10 percent threshold. The commercial refrigeration appliance leaked about 23 percent, above its 20 percent threshold, so it must be repaired. Each appliance type is measured against its own threshold.

Question 21Leak Detection

An appliance exceeds its leak rate threshold, and the owner determines that repair is not feasible. The owner must:

  1. Reduce the charge below 50 pounds
  2. Retire or retrofit it within 12 months Correct answer.
  3. Inspect it monthly and keep operating
  4. Recharge it as needed with no other action

Explanation

Where repair is not feasible, the regulation requires the appliance to be retrofitted or retired rather than left leaking indefinitely. A plan must be documented, and the work is to be completed within 12 months. Continued operation without a plan is a violation.

Question 22Leak Detection

Records used to calculate leak rates and document repairs on appliances with 50 or more pounds of refrigerant must be kept for:

  1. 1 year
  2. 5 years
  3. 3 years Correct answer.
  4. The life of the appliance

Explanation

The regulations require service and refrigerant records to be retained for three years and made available to EPA on request. Because leak rates are figured over a rolling 12-month window, three years of history supports verification. Records include amounts added, dates, and repair documentation.

Question 23Leak Detection

A system will not hold a vacuum, and the technician needs to locate the leak. The best next step is to:

  1. Add refrigerant and check with a halide torch
  2. Pull a deeper vacuum and watch the micron gauge
  3. Pressurize with nitrogen, then use a detector Correct answer.
  4. Run the compressor and check the oil level

Explanation

Leak detectors need a positive pressure differential pushing refrigerant out of the system. Once the system is pressurized with dry nitrogen, an electronic detector or bubble solution can pinpoint the leak. A vacuum only pulls air inward.

Question 24Leak Detection

A technician must pressure test an appliance holding 60 pounds of HFC-410A that has been opened for a repair. Which practice is appropriate?

  1. Vent the refrigerant to speed up the test
  2. Use the system compressor to evacuate
  3. Recover the charge, then use dry nitrogen Correct answer.
  4. Pressurize the system with oxygen

Explanation

Refrigerant must be recovered before the system is opened and before nitrogen is introduced for a pressure test. Dry nitrogen is then used with a regulator so the safe test pressure is not exceeded. This avoids both venting and the hazards of other gases.

Question 25Leak Detection

A technician uses a halide torch to check an HFC-134a system for leaks. What is the expected result?

  1. It is the most sensitive method available for HFC-134a
  2. It requires a nitrogen trace gas before it will react
  3. It works only when the system is under a deep vacuum
  4. It will not detect HFC-134a, which lacks chlorine Correct answer.

Explanation

A halide torch changes flame color in the presence of chlorine-containing refrigerants, so it is ineffective on HFCs such as HFC-134a, which contain no chlorine. Electronic detectors or bubble solution are used instead. The torch also produces combustion products and is not preferred indoors.

Question 26Leak Detection

A technician uses a halide torch to check a system containing R-22. A green tint in the flame indicates:

  1. the fuel mixture in the torch is too rich and the flame is starved of air
  2. the system is low on charge and the suction pressure has dropped
  3. air has entered the system through an open service valve
  4. chlorine-bearing refrigerant is present at the probe Correct answer.

Explanation

A halide torch draws an air sample over a heated copper element; when chlorine from a CFC or HCFC refrigerant reaches the flame, it turns green. The intensity of the green color increases with concentration, which helps locate the leak. HFCs contain no chlorine and do not produce this reaction.

Question 27Leak Detection

An ultrasonic leak detector is most useful when:

  1. the system has been evacuated to a deep vacuum and is isolated
  2. the leak is large enough that escaping refrigerant can be felt by hand
  3. the system is pressurized and refrigerant is escaping through a small opening Correct answer.
  4. the refrigerant charge has been recovered and the system is at atmospheric pressure

Explanation

Ultrasonic detectors respond to the high-frequency sound created by turbulent gas flow through a small orifice, so a pressure differential across the leak is required. They work best on small leaks that produce ultrasound rather than audible noise. With no pressure difference there is no flow and nothing to detect.

Question 28Leak Detection

Dry nitrogen is used to pressurize a system for leak testing because it:

  1. changes color as it escapes, so leaks become visible to the technician
  2. is heavier than air and settles into the lowest joints of the system
  3. is dry and inert and will not react with system materials Correct answer.
  4. carries lubricant to the compressor during the pressure test

Explanation

Dry nitrogen is nonflammable, contains no moisture, and does not react with refrigerant, oil, or system metals, so it can safely be used to build test pressure. Any moisture introduced during a pressure test would later cause acid formation and freeze-ups. Nitrogen also leaves no residue to recover.

Question 29Leak Detection

When pressurizing a system with dry nitrogen for a leak test, the technician must:

  1. open the cylinder valve fully so the test is completed faster
  2. use a pressure regulator and a relief valve set for the test pressure Correct answer.
  3. raise the low side to the full cylinder pressure to save time
  4. connect the cylinder directly to the service port with a charging hose

Explanation

A nitrogen cylinder can deliver pressures far above equipment limits, so a regulator controls the test pressure and a relief valve protects against overpressurization. Test pressure must not exceed the component's rated low-side or high-side limit. Direct cylinder pressure can rupture coils and piping.

Question 30Leak Detection

Before beginning a leak check with an electronic detector, the technician should:

  1. set the sensitivity to its lowest setting and test the largest joints first
  2. zero and adjust the instrument in clean, refrigerant-free air Correct answer.
  3. hold the probe tightly against each suspected joint and wait
  4. warm the sensor by holding it in the refrigerant vapor stream

Explanation

Electronic detectors must be zeroed in clean air so that the background reading is established and small increases in concentration are recognized. Starting in contaminated air or at an arbitrary sensitivity produces false readings. The probe is then moved slowly near the joints being checked.

Question 31Leak Detection

An electronic leak detector set to maximum sensitivity in an area with a high background concentration of refrigerant will most likely:

  1. respond only to leaks larger than one pound per year
  2. alarm continuously and make the true leak location hard to find Correct answer.
  3. shut down automatically to protect the sensor from saturation
  4. become more accurate, because higher sensitivity always finds smaller leaks

Explanation

When refrigerant is already present throughout the space, the detector responds to the background rather than to the leak, so it alarms everywhere and the source cannot be pinpointed. The technician should ventilate the area or reduce sensitivity, then confirm the location with a second method. Detectors have no automatic protection circuit for this condition.

Question 32Leak Detection

A refrigerant leak is suspected in an evaporator coil inside an air handler. A practical first step is to:

  1. shut off the blower and sample the coil and drain pan with a detector Correct answer.
  2. add fluorescent dye and check the coil right away without running the system
  3. recover the charge and cut the coil open to look for signs of oil
  4. pressurize the coil with oxygen and watch for bubbles at the joints

Explanation

Airflow through an air handler disperses refrigerant and makes pinpointing difficult, so the blower is stopped and the area around the coil, drain pan, and return is sampled. Refrigerant tends to collect in the drain pan when a coil leaks. Dye requires operating time to circulate before it can show at a leak.

Question 33Leak Detection

A soap bubble solution is applied to a joint to:

  1. confirm the total refrigerant charge in the appliance
  2. measure the leak rate in ounces per year for the leak repair records
  3. neutralize acid that has formed in the system lubricant
  4. show the location of a leak by bubbles that form at the opening Correct answer.

Explanation

Bubbles form where gas escapes from a pressurized joint, giving a clear visual confirmation of the leak point. The method is simple and reliable but works best on leaks large enough to produce visible bubbling. It does not quantify leak rate or affect system chemistry.

Question 34Leak Detection

Before charging a system that has just been repaired, the technician should:

  1. pressurize the system with oxygen to verify the repair is tight
  2. add a full charge and check for leaks after the system has run for a day
  3. skip evacuation because the repaired joint was brazed, not flared
  4. evacuate the system and perform a standing vacuum test to confirm it holds Correct answer.

Explanation

After a repair, the system must be evacuated to remove air and moisture and then isolated for a standing vacuum test to confirm the repair holds. Charging before verification wastes refrigerant and can hide a leak. Brazed joints can still leak and do not eliminate the need for evacuation.

Question 35Leak Detection

A system is evacuated to 500 microns and isolated. The vacuum rises to 1,500 microns over 10 minutes and then stays steady at that level. This most likely indicates:

  1. a faulty vacuum gauge
  2. moisture is boiling off inside the system Correct answer.
  3. the vacuum pump was left connected to the system
  4. a leak in the system

Explanation

A vacuum that rises and then holds at a higher level indicates a finite source of vapor inside the system, typically moisture boiling off under deep vacuum. A true leak admits air continuously, so the micron level keeps climbing without stabilizing. The test is repeated after the moisture is removed.

Question 36Leak Detection

A technician is leak checking a rooftop unit on a windy day and gets erratic readings. The best action is to:

  1. increase the detector sensitivity to its maximum setting
  2. shield the probe and the test area from the wind Correct answer.
  3. conclude that the unit has multiple leaks and recover the charge
  4. check the unit only while the compressor is shut off

Explanation

Wind blows refrigerant away from the leak and creates turbulent, changing concentrations at the probe, which causes erratic readings. Blocking the wind around the probe and the test area restores a stable sample. Increasing sensitivity only amplifies the erratic signal.

Question 37Leak Detection

A system pressurized to 150 psig with dry nitrogen reads 144 psig after 12 hours, and the ambient temperature fell 15 degrees F overnight. The technician should:

  1. repeat the test using oxygen instead of dry nitrogen
  2. allow for the temperature change before deciding whether a leak exists Correct answer.
  3. add refrigerant until the pressure returns to the original 150 psig
  4. conclude immediately that the system has a leak and recover the nitrogen

Explanation

Pressure in a closed system changes in proportion to absolute temperature, so a cooler night lowers the gauge reading even with no leak. The technician corrects the reading for the temperature difference before judging the test. Only a drop beyond what temperature explains indicates a leak.

Question 38Leak Detection

An electronic leak detector alarms strongly near a large leak and will not reset to zero after the leak is isolated. The technician should:

  1. move the detector to fresh air, let it clear, and re-zero it Correct answer.
  2. tap the probe against the joint to shake off the refrigerant
  3. keep searching with the detector at its current sensitivity setting
  4. replace the sensor at once, because it is burned out

Explanation

A sensor that has taken in a high concentration needs time in clean air to purge before it will respond normally again. Once it clears, it can be re-zeroed and the search continued. This is a normal recovery step, not a failure of the sensor.

Question 39Leak Detection

A system will not hold a vacuum. To determine whether the leak is in the system or in the pump and gauge setup, the technician should:

  1. evacuate the system again and watch the gauge for 24 hours
  2. perform a blank-off test by isolating the pump from the system Correct answer.
  3. add refrigerant and check every joint with a soap solution
  4. pressure test the system with refrigerant and a halide torch

Explanation

A blank-off test isolates the vacuum pump from the system and measures how deep the pump alone can pull and hold. If the pump cannot reach or hold a deep vacuum when blanked off, it or the gauges and hoses are the problem. If the pump blanks off well, the leak is in the system.

Question 40Leak Detection

A system holds a deep vacuum with no rise, but when it is pressurized with nitrogen it steadily loses pressure. The most likely explanation is:

  1. a shaft seal or gasketed joint that seats under vacuum but opens under pressure Correct answer.
  2. a vacuum pump that is too small for the volume of the system
  3. moisture that is boiling off slowly inside the evaporator
  4. air trapped in the gauge manifold between the gauges and the service valve

Explanation

Some seals and gasketed joints are pulled closed by atmospheric pressure when the system is under vacuum but are pushed open when the system is under positive pressure. This produces a system that passes a vacuum test yet fails a pressure test. The joint should be checked under pressure with a detector or bubbles.

Question 41Recovery Techniques

A technician is recovering refrigerant from a high-pressure appliance that contains 150 pounds of HCFC-22. To what level must the appliance be evacuated?

  1. 25 millimeters of mercury absolute
  2. 10 inches of mercury vacuum
  3. 15 inches of mercury vacuum
  4. 0 inches of mercury vacuum Correct answer.

Explanation

HCFC-22 appliances holding less than 200 pounds must be evacuated to 0 inches of mercury vacuum, which is atmospheric pressure. Deeper vacuum levels are required only for larger HCFC-22 charges or for other high-pressure refrigerants.

Question 42Recovery Techniques

By weight, a refillable recovery cylinder must never be filled to more than what percentage of its capacity?

  1. 80 percent Correct answer.
  2. 90 percent
  3. 70 percent
  4. 100 percent

Explanation

Refillable recovery cylinders may be filled to no more than 80 percent of capacity by weight. The remaining space allows liquid refrigerant to expand as the cylinder warms, preventing hydrostatic rupture.

Question 43Recovery Techniques

A standard DOT recovery cylinder is identified by which color scheme?

  1. White body with a green top
  2. Gray body with a yellow top Correct answer.
  3. Yellow body with a gray top
  4. Red body with a black top

Explanation

DOT recovery cylinders are gray with a yellow top, a marking that distinguishes them from cylinders of virgin refrigerant. They must also be DOT-approved, have a relief valve, and be within their test date.

Question 44Recovery Techniques

Refrigerant from one appliance is accidentally mixed with a different refrigerant in a recovery cylinder. What is the correct action?

  1. Label it as mixed and send it to a reclaimer Correct answer.
  2. Blend in virgin refrigerant until the mixture meets spec
  3. Vent the mixture to atmosphere and reuse the cylinder
  4. Return the cylinder to the supplier as virgin refrigerant

Explanation

Mixed refrigerant cannot be separated in the field and cannot be returned to a supplier as product, and it may never be vented. The cylinder must be marked as containing mixed refrigerant and sent to a reclaimer.

Question 45Recovery Techniques

Which recovery sequence removes refrigerant most quickly from a system equipped with a receiver?

  1. Recover liquid and vapor together through one hose
  2. Recover vapor only until the system reaches 0 psig
  3. Pull liquid from the receiver first, then recover vapor Correct answer.
  4. Recover vapor first, then finish with the liquid

Explanation

Liquid carries far more refrigerant per unit volume and transfers much faster than vapor. Removing the bulk as liquid first and finishing with vapor minimizes total recovery time.

Question 46Recovery Techniques

Which use of an appliance's own compressor is allowed when removing refrigerant?

  1. Moving the bulk of the charge into a recovery cylinder Correct answer.
  2. Pulling the appliance down to the required final vacuum
  3. Establishing the deep vacuum required before opening the system
  4. Substituting for a certified recovery machine in every case

Explanation

EPA allows the appliance's compressor to be used to move the initial charge into a recovery cylinder. It may not be used for the final evacuation, because a compressor cannot pull the system to the required vacuum and may be damaged.

Question 47Recovery Techniques

Recovery equipment used on Type II appliances must be certified to which standard?

  1. AHRI 740 Correct answer.
  2. ASHRAE 15
  3. AHRI 700
  4. ASHRAE 34

Explanation

Recovery and recycling machines must be certified by an EPA-approved laboratory to AHRI 740, formerly known as ARI 740. AHRI 700 is a separate specification covering the purity of reclaimed refrigerant.

Question 48Recovery Techniques

How long must an employer keep records of refrigerant purchased and refrigerant recovered?

  1. 5 years
  2. 3 years Correct answer.
  3. 2 years
  4. 1 year

Explanation

Employers must retain records of refrigerant purchased and of refrigerant recovered, recycled, or reclaimed for three years. These records are used to verify compliance during inspections.

Question 49Recovery Techniques

R-410A must be recovered with equipment and hoses that are:

  1. Equipped with standard flare fittings only
  2. Certified only for CFC refrigerants
  3. Rated for the higher pressures of R-410A Correct answer.
  4. Interchangeable with R-22 equipment if used briefly

Explanation

R-410A operates at substantially higher pressures than R-22, so hoses, gauges, recovery machines, and cylinders must all be rated for it. Under-rated equipment can rupture and injure the technician.

Question 50Recovery Techniques

What is the maximum temperature of a water bath used to warm a refrigerant cylinder?

  1. 125°F Correct answer.
  2. 100°F
  3. 175°F
  4. 150°F

Explanation

Cylinders may be warmed only with warm water or a heating blanket, and the bath temperature must not exceed 125°F. Open flames and torches are never permitted because of the risk of rupture.