Experimental and theoretical analysis of flashing water flow through a safety valve

A set of experiments has been carried out on the model of the CROSBY safety valve for flashing and nonflashing water flow. The pressure distribution inside the valve, the inlet and outlet temperatures and the mass-flow rate have been measured. The characteristics of the valve giving the mass-flow rate as a function of the square root of the pressure drop are given. The experimental results were compared with equilibrium and relaxation two-phase flow models. The nonequilibrium character of fast evaporation and its substantial influence on the two-phase flow behaviour has been emphasized. This could constitute a comprehensive base for a better understanding of two-phase flow through safety valves.