How is work quench valve in reefer?

A refrigeration circuit is provided with a quench line connecting the liquid line and the suction line and containing a QEV. The QEV is controlled responsive to the superheat of the refrigerant supplied to the compressor. By injecting liquid refrigerant downstream of the suction modulation valve and the sensor for the TXV, the system can be operated at low capacity without overheating the compressor oil.