Compressor mode means the operational and pressurized status of a compressor. For a centrifugal compressor, mode refers to either operating-mode or not-operating-depressurized-mode. For a reciprocating compressor, mode refers to either: Operating-mode, standby-pressurized-mode, or not-operating-depressurized-mode.
40 CFR § 98.238
Except as provided in this section, all terms used in this subpart have the same meaning given in the Clean Air Act and subpart A of this part.