Influence of vent pipes downstream of the limiting orifice. Rupture discs
Calculating vents: DIERS methods - Gassy Reactions

As explained in the case of reaction systems with high vapor pressure, vent lines are required downstream of the limiting orifice, to direct the gas-liquid two-phase discharge towards a buffer capacity for collecting the liquid fraction of the two-phase discharge. These vent lines have the effect of reducing the capacity of the vent to protect the upstream reactor or vessel.

This effect results in a mass flow reduction factor$\frac{G_C}{G_{0C}}$ applied to the critical mass flow G_0C calculated for the ideal vent surface orifice A₀.

The calculation method presented below applies to vent lines located downstream of a rupture disk. The case of valves will be dealt with in...