Process vent
Process vent means a vent from a process vessel or vents from multiple process vessels within a process that are manifolded together into a common header, through which a controlled substance-containing gas stream is, or has the potential to be, released to the atmosphere (or the point of entry into a control device, if any). Examples of process vents include, but are not limited to, vents on condensers used for product recovery, bottoms receivers, surge control vessels, reactors, filters, centrifuges, and process tanks. Process vents do not include vents on storage tanks, wastewater emission sources, or pieces of equipment.
Source
40 CFR § 82.3
Scoping language
As used in this subpart, the term: