The Hand Diaphragm Primer is a manual air pump designed to create vacuum in the priming line of a centrifugal pump, allowing water to be drawn into the pump for proper priming. It features a flapper check valve within the diaphragm and a bottom disk check valve to control airflow. During operation, air enters through the bottom check valve on the upstroke and exits through the diaphragm valve on the downstroke. The diaphragm is actuated by a connecting rod with an eyebolt attached to a fulcrum handle bracket. Features: Lightweight aluminum alloy construction Simple installation on most centrifugal pumps Heavy-duty rubber diaphragm for durability Integrated drain valve for easy maintenance