Core of the matter
These are used for new refrigerant
Disposable cylinders
According to ASHRAE standard 34 refrigerant safety classifications, these are the most dangerous
This is restricted to technicians who are EPA certified in refrigerant recovery.
Sale of refrigerants
On refrigeration units that use an open compressor; this is most likely to leak if the unit is not used for several months.
the rotating shaft seal, or compressor shaft seal
When evacuating a system, the use of too large a vacuum pump can cause this.
Trapped water in the system to freeze.
This is colored red on a manifold gauge set
High Pressure Gauge
This type of oil that is most commonly used in stationary refrigeration applications with HFC-134a refrigerant.
Ester-based oil
In a refrigeration system, the component directly following the evaporator is the ______.
Accumulator
A local municipal water supply, should be used as the primary water source for cooling for this.
the condenser of a water-cooled recovery unit
These steps may be taken to prevent air accumulation into an idle low pressure refrigeration system.
System pressure should be maintained slightly above atmospheric.
A refrigerant mixture that acts like a single-component refrigerant over its entire range is called
Azeotropic
Under the conditions of ARI 740-1993, recovery devices that were manufactured after November 15, 1993 and are used for recovery of refrigerant from small appliances must be capable of this
recovering 90% of the refrigerant when the compressor is operating or achieving a 4 inch vacuum
R-410A requires a high-pressure manifold gauge and hose set. They must have what ratings per the EPA
4000 psig burst pressure and 800 psig working pressure.
The evaporation temperature of R- 410a at 100 psig is approximately this.
30 degrees F.
Commercial and industrial process refrigeration systems must be repaired when the leak rate exceeds what percent of the charge per year.
Thirty percent / 30 %
These leak from a system in uneven amounts due to different vapor pressures.
Blended refrigerants (zeotropic)
These conditions can cause excessive pressure on the high side of an active self-contained recovery device
a closed recovery tank inlet valve, and/or excessive air or other non-condensables in the recovery tank
The proper charging method for blended (non-azeotropic) refrigerants (400 Series) is to use a remove the charge from the cylinder as a what?
Liquid
excessive superheat on a high-pressure system is an indicator of this.
Excessive superheat
System water pumps, the recovery compressor, and the recovery condenser water should all be on _____.
When recovering vapor from a low pressure refrigeration system
These gases helps form Earth's protective shield from UV radiation.
Stratospheric ozone
EPA regulations require the capture of at least 80% of the refrigerant from a small appliance with a non-operating compressor if the technician is using this.
a system-dependent (passive) recovery unit or a self-contained (active) recovery unit.
In a refrigeration system with a TXV, the component directly following the condenser is this.
Liquid Receiver
When there is excessive moisture collecting in the purge unit of a low pressure refrigeration system indicates this.
the condenser or chiller barrel tubes are leaking.
Both CFC-11 and HCFC-123 chillers require purge units because of this.
the system operates below atmospheric pressure