A technician needs to access the sealed system of a household refrigerator that has no service valve. What tool is commonly used to gain temporary access for recovery?

Giải thích

Small sealed appliances often lack service ports, so technicians attach a piercing (saddle) valve to a process stub or copper line to access the refrigerant for recovery. A piercing valve should be used only temporarily because it can leak over time. After service the access point is typically brazed closed rather than left on a bolt-on piercing valve.