8 Type III Certification Practice Free Online FlashCards

What appliances does Type III certification focus on?

Type III certification covers servicing, repairing, and disposing of low-pressure appliances, especially centrifugal chillers.

Why can low-pressure chillers draw air and moisture through a leak?

Because the system may be below atmospheric pressure, a leak can draw air and moisture inward.

What can excessive purge-unit operation signal?

Excessive purge-unit operation can signal that air is leaking into the low-pressure system.

What is the preferred way to raise pressure for a low-pressure leak test?

Controlled heating, such as hot water or a built-in heating device, is the preferred way to raise pressure for a low-pressure leak test. Nitrogen is another method where permitted.

What is the maximum leak-test pressure for a low-pressure centrifugal chiller?

A low-pressure centrifugal chiller must not be pressure-tested above 10 psig.

What is a limitation of a pressure-decay test?

A pressure-decay test can show that pressure is dropping, but it cannot pinpoint the leak's location.

In what order should refrigerant be recovered?

Recover liquid refrigerant first, then recover vapor; removing liquid first speeds recovery.

What should be done with chiller water during evacuation?

Circulate or remove chiller water as needed to prevent it from freezing during evacuation.

How should oil be prepared before removal?

Heat the oil to 130°F before removing it to reduce refrigerant release.

What should you do if pressure rises after reaching the recovery vacuum?

A pressure rise can mean refrigerant remains in the system or is boiling out of the oil; continue recovery as needed.

What is the normal evacuation endpoint for a low-pressure appliance?

For normal opening or disposal, evacuate a low-pressure appliance to 25 mm Hg absolute, regardless of the recovery equipment's manufacture date.

What pressure condition applies before a qualifying non-major repair?

For a non-major repair that will not be followed by evacuation to the atmosphere, pressurize the appliance to no higher than 0 psig before opening, using a method allowed for that refrigerant.