Often, there is a concern about oil mixing with the medium being compressed, whether a refrigerant or a process gas. Packagers of oil-flooded screw compressors will include a separation vessel that usually reduces oil carryover to 5 to 10 parts per million (ppm). For most industrial refrigeration applications, this level of oil carryover is acceptable as oil can easily be recovered from the low side of the refrigeration system. For applications where oil recovery is difficult, such as refrigerant evaporating temperatures below approximately -60°F (-51°C), secondary oil separators are often supplied to reduce the oil carryover to well below 1 ppm.

See the related feature article, "Using Oil-Flooded Screw Compressors for Industrial Refrigeration," to learn how oil-flooded screw compressors can be efficiently and effectively applied in industrial refrigeration applications.