Equation (8) is a dynamic relation of the temporal change in
shell pressure due to the:
a) Influx of fluid from the tube rupture (first three terms on the
numerator);
b) Shell fluid flowing in and out of the shell via the attached
piping and the PSV (last three terms on the numerator);
c) Compressibility of the flashed fluid from the tube-side in the
shell (first three terms on the denominator);
d) Compressibility of the shell fluid (fourth term on the
denominator);
e) Compressibility of the attached capacitance (accumulators
and other equipment) to the shell-side (fifth term on the
denominator); and
f) Compliance of the shell material (last term on the
denominator).