3/4" HVAC AC SIGHT GLASS O.D. FLARE WITH MOISTURE Features: SIGHT GLASS 3/4 " O.D. FLARE WITH MOISTURE O.D: 3/4" Pipe Diameter: 3/8" This Sight glasse ensure a fast and safe inspection of the conditions of the refrigerant fluid. Allow to determine the state of charge, Detect restrictions in the system, Find the presence of moisture Detect if the oil return to the compressor crankcase, This and all of the sight glasses should be located as close as possible to the expansion valve. More information about sight glass What is a Sight Glass? For optimum performance a cooling system must have a solid column of light at the expansion valve. Sight Glasses are used to determine the state of charge. Sight glasses and moisture liquid indicators ensure a fast and safe inspection of the conditions of the refrigerant fluid in the circuit concerning regular flow and moisture. Liquid indicators also ensure inspection of the regular return of oil to the compressor crankcase. A sight glass provides a visual indicator of any "bubbles" in the refrigerant stream that could adversely affect performance. If the charge and working condition are normal, the refrigerant fluid appears perfectly liquid underneath the "lens" of the indicator. The presence of bubbles indicates that the refrigerant fluid is partial evaporating along the liquid line. The sight glass will show bubbles if the system is low on refrigerant. The sight glass may show a few bubbles when the system first starts. Or, they may appear just as the system stops. These are normal equalizing actions and do not indicate a shortage of refrigerant. Bubbles may also show a restriction in the circuit ahead of the sight glass. This may be due to a partially clogged drier, screen, or filter. The sight glass has long extensions that permit soldering or brazing the joints without injury to the sight glass. Some sight glasses are built into a suction line or liquid line filter-drier. Sight glasses also incorporate a visual moisture indic