A flow splitter (10) that is uniquely characterized by the use of two diaphragm valves in a single valve body that are arranged in opposition to one another. The diaphragm valves are coupled together for common movement by a coupler, such that the flow rate through respective outlets is a function of the position of either diaphragm valve. That is, the position of one valve is a function of the position of the other valve, and vice versa. With this construction a single actuator can control the ratio of total flow that will be delivered to each of two outlet ports. Moreover, such construction eliminates the need for thermal or pressure sensors and thus the drawbacks associated therewith.