Good day everybody. I don't know if you can help. I have just been to a imi Celler cooler.with a cu 50 2hp outdoor unit on r 22. Does anyone know what the expansion device is on these.it is about 10 years old.when it's running there is some sort of fitting on the liquid line after the drier just as it goes into the evaporator and it is frosting from there into the evaporator. Is this normal.cheers.