Jul 29, 2018 Often in commercial HVAC and refrigeration, you will either find or install sight glass/moisture indicators. The sight glass portion is simple, it’s just there to show if the liquid line has a full line of liquid or if it has bubbles which shows it’s a liquid/vapor mix. A clear glass on a running system generally means. Castel sight glasses CO2 indicate by means of a visual indication whether there is moisture in the refrigerant. In the case of a yellow sight glass, moisture is present and the filter drier must be replaced. It is advisable to place a valve after the sight glass so that you can easily replace the filter drier.
Bubbles normally means air intrusion into a system. If it isyour air conditioner, then you most likely have a cooling coilleak. Other systems would be were you are drawing a vacuum.
This ismost likely at the suction of a pump or compressor. Good luck!Actually, the bubbles could be completely normal. On the highpressure side, bubbles simply mean not all the high-pressurerefrigerant has condensed. Some of it remains as vapor. It couldmean you are low on refrigerant, or the high side temp is too high(blocked condensor maybe). In an auto, it is not unusual to have afew bubbles in the sight glass unless you're driving or have a bigfan forcing ais across the condensor. There are several reasons forbubbles in the sight glass.
If one of the traditional refrigerantsshowed vapor in the sight glass it often meant there wasn't enoughliquid refrigerant being fed to the valve, and more refrigerant wasadded to the system. Blends could show flashing for the samereason, however, they can also flash when there is plenty of liquidin the receiver. Ironically, this liquid in the receiver could becausing the problem, particularly when the equipment is in a hotenvironment.
Blends will come out of the condenser slightlysubcooled - at a temperature below the saturated temperature of theblend at the existing high side pressure. Yet when the blend sitsin the receiver, it can 'locally fractionate,' or changecomposition slightly by shifting one of the components into thevapor space of the receiver. This will effectively produce asaturated liquid in the receiver, at the same pressure you hadbefore, which flashes when it hits the expanded volume of the sightglass. In most cases these bubbles will collapse when the blendgets back into the tubing which feeds the valve, and the systemwill operate just fine. Check other system parameters such aspressures, superheat and amperage to confirm whether you have theright charge. Don't rely solely on the sight glass.
Bubbles normally means air intrusion into a system. If it isyour air conditioner, then you most likely have a cooling coilleak. Other systems would be were you are drawing a vacuum. This ismost likely at the suction of a pump or compressor. Good luck!Actually, the bubbles could be completely normal. On the highpressure side, bubbles simply mean not all the high-pressurerefrigerant has condensed.
Some of it remains as vapor. It couldmean you are low on refrigerant, or the high side temp is too high(blocked condensor maybe). In an auto, it is not unusual to have afew bubbles in the sight glass unless you're driving or have a bigfan forcing ais across the condensor. There are several reasons forbubbles in the sight glass. If one of the traditional refrigerantsshowed vapor in the sight glass it often meant there wasn't enoughliquid refrigerant being fed to the valve, and more refrigerant wasadded to the system. Blends could show flashing for the samereason, however, they can also flash when there is plenty of liquidin the receiver. Ironically, this liquid in the receiver could becausing the problem, particularly when the equipment is in a hotenvironment.
Blends will come out of the condenser slightlysubcooled - at a temperature below the saturated temperature of theblend at the existing high side pressure. Yet when the blend sitsin the receiver, it can 'locally fractionate,' or changecomposition slightly by shifting one of the components into thevapor space of the receiver. This will effectively produce asaturated liquid in the receiver, at the same pressure you hadbefore, which flashes when it hits the expanded volume of the sightglass. In most cases these bubbles will collapse when the blendgets back into the tubing which feeds the valve, and the systemwill operate just fine. Check other system parameters such aspressures, superheat and amperage to confirm whether you have theright charge. Don't rely solely on the sight glass.