Abstract: A low pressure fluctuation control apparatus comprises a liquid recirculation loop comprising a dip tube, a diaphragm or bellows type pump, a first regulator, a first flow meter, a junction, and a return tube. A back pressure controller is located in the return tube. In addition, the apparatus comprises a material supply line fluidly connected the liquid recirculation loop via the junction. A flow control system is located in the material supply line. The recirculation loop draws liquid from a supply container by the dip tube, and returns a portion of the liquid to the supply container by the return tube. The backpressure flow controller regulates the flow rate of the liquid, thereby steadying fluctuations in the liquid being supplied.

Abstract: This invention provides apparatuses and methods to supply a steady volume of liquid with low pressure fluctuation that can be used to form a liquid blend or to supply other equipment or tools. The invention uses a flow controller that controls the flow rate for liquid that is fed to a liquid supply pipe from a recirculation loop that is connected thereto, the recirculation loop has a dip tube for insertion into a liquid supply container, pump, and liquid backpressure control device.