Abstract: This disclosure describes a removable flow control device which may be used in a rotating flow supply system in a gas turbine to optimize coolant flow by improving flow dynamics, reducing leakage of coolant, and reducing pressure loss in the flow supply system. The flow control device may be coupled to a blade and rotor assembly and may include a flow modifier for directing flow through a junction at which cooling channels intersect and are in fluid communication. The device may direct, control, meter, channel, or otherwise modify the flow of coolant, and may be coupled to the blade and rotor assembly independently of other blade components so that coupling and decoupling the flow control device does not require modification or de-stacking of the rotor assembly.