PURPOSE: To provide a refrigerant flow control device simple in structure and reliable as well as economically manufacturable and efficient, by preventing a refrigerant gas from bypassing.

CONSTITUTION: A refrigerant flow control device comprises a float 28 that is responsive to a liquid level of a liquid refrigerant to control a refrigerant flow from a lower portion of a condenser 12, and a valve body 27 that is a standpipe 32 extending upwardly from a lower portion of a sump, the standpipe having its upper end closed and having near its lower end an opening formed to provide fluid communication to a refrigerant return line 22. The valve body 27 comprises slots 36 on the lower side surface thereof so that when the liquid level of refrigerant is below a predetermined level, the float 28 is caused to rest at a vertical height on the standpipe such that it covers the slots 36, and when the liquid level of refrigerant rises above the predetermined level, the float 28 is caused to slide upwardly to uncover the slots 36 and allow liquid refrigerant to flow from the sump.