Definition(s)
Vent Stack
Elevated vertical termination of a disposal system that discharges vapours into the atmosphere without combustion or conversion of the relieved fluid.
Source: API STD 521, Pressure-relieving and Depressuring Systems, Sixth Edition, January 2014. Global Standards
Source: API STD 521, Pressure-relieving and Depressuring Systems, Fifth Edition, January 2007 (Addendum May 2008). Global Standards