Parallel Racks: Oil

From the discharge line, the oil-refrigerant mixture goes into a large cylinder called the oil separator. As its name suggests, the oil separator removes the oil from the refrigerant; the filter may be inside the separator or beyond it. (In this video, the filter is inside the separator.)

At the bottom of the separator, there is an oil float. From there, the oil moves through a pipe back to the oil reservoir. Some reservoirs, like the one in this video, have a sight glass before the inlet that allows you to see the oil going into the reservoir. There will also be some sight glasses on the reservoir that allow you to see the oil level inside the reservoir.

From the reservoir, a pipe carries the oil to the oil regulators on each compressor. You can use those regulators to adjust the oil level for each individual compressor. These regulators usually also have a sight glass.