The clog capillary tubing
Recently, the failure of domestic refrigerators, caused by clogging of the capillary tube (CT) was not almost observed. These were isolated cases, has in its basis the "mechanical" nature (metal swarf and other). Carried by a stream of refrigerant, these particles circulate freely through the system and, in case of occurrence of adverse factors(emissions in the oil system or its breakdown products, kinks in the passage of the pipe), could create a slight narrowing of the passage CT. As the particle size of the blockage was relatively high, it was fast enough to overlap the narrow passage of the capillary tube and a serious violation of circulation of the refrigerant. Concerned consumers off the machine and call the wizard. Since tube blockage did not have time to significantly thicken or increase in volume, problems with removal of the defect "clog the capillary tube" special difficulties were presented. However, since the mid 90-ies, when started active promotion of new designs of compressors with a high tolerance of heat and new brands of oils, appeared refrigeration equipment designed for operation with refrigerant R-134a. As a result of failures in refrigerators, caused by blockages in CT, has become much more. This was mainly due to the fact that these devices have been used CT with reduced internal diameter (from 0.8 to 0,71...to 0.66 mm). It is known that the reduction of the internal diameter CT requires improving the quality of production refrigeration unit. The first few years of operation of such devices did not reveal any significant differences in the equipment operating on refrigerant R-134a and R-12, except that technique on R-12 withstood variations in ambient temperature in a wider range. However, in five years from the date of commencement of operation have refrigerators with defect "clog the capillary tube". These blockages often was difficult to remove the blockages in CT not "dented" even excessive system pressure of 150 kgf/cm2 and above! A harbinger of complete clogging of the capillary tube is the appearance of a partial obstruction, which without the presence of devices (sensitive manometer)is very hard to diagnose. The ideal instrument necessary for the qualitative diagnosis of partial clogging of the capillary tube is rotameter (flow meter, which can measure the flow rate passing through the CT gas in l/min).
But they are rare, and the need for their application occurs not so often. Further study of this problem led me to the conclusion that it is not always possible to accurately and unambiguously say that blockages in CT caused by design features refrigeration units (HA), for example, in cases of deviation mode HA from nominal. It seems that this side of the defect caused by the use of the refrigerant R-134a as imported and domestic household refrigerators operating on other types of refrigerants such a defect does not have.
the most interesting Thing that the producers have not announced by the chemical or physical nature of the blockage CT in their models. It was the only reference to models of STINOL refrigerator compressors QUO: the precipitation of paraffin oils. It seems that there's just no one to do first with manufacturers is the sale of new models. But in vain - master, who knows the problem of clogging in some infamous line of refrigerators, may advise the client to buy the device from another manufacturer. Let us dwell on the possible causes of blockages in CT.