Abstract: To achieve priming during start-up and repriming during operation, a self-priming pump system is provided. The self-priming pump system includes a discharge priming reservoir for storing priming liquid for a pump. The discharge priming reservoir has an inlet in communication with the outlet of the pump for receiving priming liquid from the pump and has an outlet in communication with the pump upstream of an impeller and downstream of a liquid supply reservoir for supplying the priming liquid to the pump. The self-priming pump system is operable to separate air from priming liquid in the discharge priming reservoir during recirculation of priming liquid. In addition, a priming valve is disposed between the discharge priming reservoir and the pump to control circulation of priming liquid through the self-priming pump system.