Closed-vent system
Closed-vent system means a system that is not open to the atmosphere and is composed of hard-piping, ductwork, connections, and, if necessary, fans, blowers, or other flow-inducing devices that conveys gas or vapor from an emission point to a control device.
Source
40 CFR § 63.681
Scoping language
All terms used in this subpart shall have the meaning given to them in this section, 40 CFR 63.2 of this part, and the Act.