It is easy to take brazed joints apart using the same method by which they were joined.
Heat the joint with a torch until it becomes cherry red in color, and then grab the tubing near the joint with a pair of pliers and pull it apart.
It will be necessary to disassemble the tubing for replacement of the compressor or any other part in the sealed system. Before removing the old part, you can use this method to disconnect the tubing.
CAUTION: Before applying heat to any joint, it is imperative to evacuate all the gas (Freon) in the system. To do this, use an access valve.
Instead of connecting tubing by swaging before brazing, special couplings can be used to join tubing of similar or different sizes by silver brazing. Figure 24 illustrates some of these couplings. They are available in most tubing sizes.
Flared connection. This is a metal-to-metal connection without the use of a solder. To create a flared connection, the ends of the tubing to be joined should be cut straight and square with a tubing cutter (fig. 17) to prevent an off center and, consequently, leaky joint. To do this, the tubing must be held securely while cutting. Use a small vice, C-clamps or Vice-Grip pliers. Then ream the inside of the cut to make it smooth. Most tubing cutters have a reamer attached. The tubing may also be cut with a fine-tooth hacksaw (thirty-two teeth/inch) (see fig. 18). When using either method, make sure that no chips or shavings remain inside the tubing.
Flaring couplings. The flared fitting relies on the airtight connections of the fittings rather than brazing. The fittings are a flared half union coupling and two female flare nuts. They are retained on the tubing by a small flaring on each of the ends to be joined. For this type of connection, a different set of tools is needed from those used in making a brazed connection. They are inexpensive and available almost everywhere in hardware and refrigeration supply stores. (See figs. 24a and 24b.)