(148a) API-RP521 Psv Capacity Calculation Compared Against Universal Bernoulli's Homogeneous Equilibrium Method

Bernoulli's Homogeneous Equilibrium (HEM) Method is used to compute relief valve capacity for liquids, vapors and two-phase flows. HC liquids, vapor, water, steam and two phase flow of water and water vapor as well as HC vapor and HC liquid are considered at set pressures ranging from 50 psig to 1500 psig. The calculated coefficents of discharge by HEM method are compared against industry practise coefficients of discharge that are recommended by API-RP521. While the coefficients are comparable, there are differences that are noteworthy.