Hi Zapata, the objective that this capillary meets through the center of the suntion or return pipe, is none other than that of exchanging heat, so that the liquid refrigerant that circulates through it reaches the lowest temperature, to the evaporator and as a result to the east expand inside the evaporator itself, absorb even more heat than a capillary that does not do this exchange. If what you need is to replace that capillary with another one, this one can be connected on the outside, but (EYE) if it is a system that does not have an external condenser, such as old refrigerators, that is, if that condenser is not visible on the outside, I recommend even that it leads to spend a little more work that you try to install it in the same way, so that you achieve better cold, since in these cases it is necessary that the capillary is inside. Keep in mind that the internal condensers, printed inside the furniture of the equipment, manage to avoid corrosion, by humidity, but they are not at all efficient in hot countries when it comes to dissipating heat, pate of this heat is absorbed by the compressor, when exchange heat the refrigerant that returns from the evaporator with which it is liquefied inside the capillary towards it. In addition, depending on how uncomfortable it is for the job, to make internal welds inside or surrounded by plastics, it can also be useful not to have to open extra holes, which can damage some internal pipe, if it is to make them, to remove said capillary outside. I recommend you cut the return tube inside the freezer cabinet at one point if it is allowed intermediate between the copper and aluminum tie, the evaporator and the entrance of the pipe to the equipment cabinet, then expand it so that you can insert the capillary and The evaporator pipe, then welded and finished, you can use metal sheets to avoid welding heat, damaging the freezer cabinet. Then do the same before entering the other end of the return pipe to the compressor, expand and remove the capillary from that end. Well I hope something worth this comment. S @ lu2s friovega63.