Why is it a good idea to remove Schrader stems from service valves prior to evacuation?

Which of the following is true regarding refrigerant leaks on small appliances?

Type I Certification is required for;

The sale of CFC and HCFC refrigerant is ;

System-dependent or passive recovery equipment;

A small appliance is defined by EPA as;

Hydrochlorofluorocarbons (HCFC) refrigerants contain:

Which of the following is an example of a non-condensable?

Which refrigerant is a chlorine- free refrigerant?

After the refrigerant has been recovered, which of the following can be used to flush the system?