This article looks briefly at a series of experiments in which heated refrigerant F113 was discharged through a relief valve. The heated fluid was stored under pressure in a piston type accummulator and then rapidly discharged across a relief valve into a large blowdown tank.The tests demonstrate fiat the valve acts as an orifice. The fluid flow rate is proportional to the square root of the pressure difference across the valve and the dada forh heated and cold refrigerant both lie on the same curve. However, the discharge area-a-at the valve seat depends on both the npstream pressure and the flow through the value.