Q700. Should material vented to a flare on a daily or otherwise frequent basis due to the cyclic operation of certain units be considered a startup, shutdown, or malfunction (SSM) event in Equation Y-3?

A700. The SSM flow portion of Equation Y-3 was intended to cover unusual events associated with the startup, shutdown, or malfunction (SSM) of a unit.  We did not intend for this term to include routine gases that are sent to the flare on a daily or otherwise frequent basis due to the cyclic operation of a delayed coking unit or catalytic reforming unit.  We do not consider delayed coking drum cycling or cyclic catalytic reforming unit regeneration operations to be shutdown events as the process unit remains in operation.  These routine purges that may be sent to the flare should be accounted for in the “normal” flare flow term (Flare_Norm) within Equation Y-3, regardless of the quantity of gas purged per day.