Type II recovery & evacuation levels: EPA 608 Practice Questions

Using recovery equipment made after November 15, 1993, to what level must a high-pressure appliance with less than 200 lb of refrigerant be evacuated before a major repair?

Table 1 lists 0 in Hg for high-pressure appliances (or isolated components) under 200 lb, for both older and newer recovery equipment.

Using recovery equipment made after November 15, 1993, to what level must a high-pressure appliance with 200 lb or more be evacuated before a major repair?

High-pressure appliances of 200 lb or more go to 10 in Hg with post-1993 equipment, or 4 in Hg with pre-1993 equipment.

Using recovery equipment made before November 15, 1993, to what level must a high-pressure appliance with 200 lb or more be evacuated?

For pre-1993 recovery equipment, Table 1 lists 4 in Hg for high-pressure appliances of 200 lb or more.

A medium-pressure appliance using R-134a holds 120 lb. Using modern recovery equipment, to what level must it be evacuated before a major repair?

Medium-pressure appliances under 200 lb go to 10 in Hg with post-1993 equipment (4 in Hg with older equipment).

A medium-pressure R-134a chiller holds 450 lb. Using modern recovery equipment, to what level must it be evacuated before a major repair?

Medium-pressure appliances of 200 lb or more go to 15 in Hg with post-1993 equipment. 25 mm Hg absolute applies only to low-pressure appliances.

To what level must a very high-pressure appliance, such as an R-23 ultra-low-temperature freezer, be evacuated?

Table 1 lists 0 in Hg for very high-pressure appliances with any recovery equipment.

Before a non-major repair on a high-pressure appliance, with no release expected afterward, to what level must it be evacuated?

For non-major repairs not followed by an evacuation to the atmosphere, medium-, high- and very high-pressure appliances are evacuated to at least 0 psig.

A technician leaves a 6-square-inch opening in a system uncovered for 20 minutes. How is this repair classified?

An opening of more than 4 square inches of flow area left uncovered for more than 15 minutes makes the work a major repair, requiring full Table 1 evacuation.

Replacing the compressor on an R-454B heat pump is which kind of repair?

Removing the compressor, condenser, evaporator or an auxiliary heat exchange coil is always a major repair.

To change the oil in a high-pressure appliance, to what level must the appliance (or the receiver the oil drains into) be evacuated?

For oil changes, the appliance is evacuated or pressurized to no higher than 5 psig, or the oil is drained into a receiver held at no higher than 5 psig.

On a large system with a receiver, where is liquid refrigerant best recovered from?

Liquid collects in the receiver and liquid line, so recovering liquid there first moves the most refrigerant in the least time.

A system's service valves let the technician pump the refrigerant into the condenser and receiver. What must be done before opening the isolated evaporator section?

Technicians may evacuate either the whole appliance or just the isolated part being opened, to the Table 1 level for that part.

When recovering from a system with a water-cooled condenser, why should water keep flowing through the condenser?

As pressure drops, the refrigerant boils at low temperatures and can freeze the water in the tubes. Circulating water, or draining it, prevents tube damage.

How does the push-pull method recover liquid refrigerant?

The machine pulls vapor from the cylinder and pushes it into the system's vapor side, which pushes liquid into the cylinder without passing through the machine's compressor. Vapor must still be recovered afterward.

An 18-lb R-454B rooftop unit needs a new evaporator coil. Using a recovery machine built in 2022, to what level must it be evacuated?

R-454B is a high-pressure refrigerant and the charge is under 200 lb, so Table 1 requires 0 in Hg for this major repair.