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    HVAC Systems · Refrigeration — Walk-In & Commercial

    Oil Return

    The carrying of compressor oil back through the system by refrigerant velocity. Suction lines and risers must maintain a minimum vapor velocity so oil does not log in the evaporator and starve the compressor.

    Safety note

    Oversized or improperly trapped suction risers lose velocity and can cause oil starvation and compressor failure.

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