US Patent 7997348 Foam proportioning system with low-end controller

Embodiments of the invention provide a foam proportioning system. The foam proportioning system can include a foam pump, at least one foam line, a divert, and at least one controller. The divert can direct a portion of a flow of a liquid foam concentrate downstream of the foam pump back through the foam pump. The controller, which can be in communication with the foam pump and the divert, can be configured to automatically maintain a minimum flow rate of the liquid foam concentrate through the foam pump.