Before you can cut the system open, you need to recover the refrigerant. Here are the items seen in the above photo:

• Recovery machine. This thing is simply a compressor and a condensor in a box. It compresses the refrigerant gas from the system, cools it to convert it to a liquid for storage in the recovery tank. This one uses an oilless compressor which is more durable that the type of units that use a hermetic compressor.
• Recovery Tank. To use the tank it is first pumped down to a good vacuum using a two stage pump.
• Fish Scale. The scale is used to get the gross and net weights of tank and the refrigerant that you remove from the system. Later the weight can be used to evaluate whether the system was over or under charged.
• Gauge Manafolds. These are used to connect into the pressurized refrigerant system. Valves on the gage manifold allow the changing of the pressure levels and amounts of refrigerant in the system. Gauges are used to read the refrigerant pressure and have P/T tables used to determine the refrigerant temperature. Here they are being used to direct the flow of recovered refrigerant liquid and vapor.