Abstract: A fluid proportioning valve meters a flow of secondary fluid into a flow of primary fluid in a predetermined, controllable proportion of secondary fluid to primary fluid and in a predetermined, controlled volume flow of secondary fluid responsive to volume flow of primary fluid. The fluid proportioning valve includes: a housing defining a conduit in operation for flow of secondary fluid from an inlet in communication with a source of secondary fluid towards an outlet in communication with a source of primary fluid; a first valve element disposed within the housing and defining a first valve opening between inlet and outlet; and a second valve element disposed within the housing and defining a second valve opening between inlet and outlet.