Definition(s)
Enclosed Flare
Enclosure with one or more burners arranged in such a manner that the flame is not directly visible.
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