The Series HFO Flow Alarm provides continuous monitoring and control of flow rate levels. The flow alarm can be configured to open or close a contact for an increasing or decreasing set point. The unit includes two 10A SPDT limit switches with field adjustable alarm settings. Integral direct reading scale provides local indication of flow rate. The flow alarm is designed to mount in any orientation and does not require inlet or outlet straight plumbing. The Series HFO is constructed with a rugged cast aluminum NEMA 4X (IP65) enclosure for installation outdoors or in harsh environments.