Purged Cabinets An electrical cabinet 6' high x 36" wide x 18" deep must be supplied with a rapid purge rate when the cabinet is initially closed after being open. The rapid purge rate must displace four volumes of the cabinet size in 2 min. During the high purge rate the air is carried out of the cabinet through a safety valve set at 0.3" WC. The cabinet maintains a 0.1" WC pressure with a 0.67 scfm air flow during normal purging rates. Use the equation F = CX VAP to calculate air flow. 1. What low flow rate is necessary to develop 0.2" WC pressure after the initial high flow purge? 2. What rapid purge rate is needed?