Abstract: A device for dispensing a chemical solution into a pipeline transporting a liquid under pressure irrespective of whether the liquid pressure varies between a maximum and a minimum or is subsantially constant. The volume of solution dispensed is varied at times when the liquid pressure is varying by selection of an aperture from a plurality of apertures at varying axial positions, for placing the interior of the pipeline in communication with the interior of the enclosure above the solution level, at times when the level drops axially to the selected apertures; or, at times when the liquid pressure is substantially constant, by adjustment of the amount of liquid permitted to enter the device.

Abstract: A device for dispensing a chemical solution into a pipeline transporting a liquid under pressure irrespective of whether the liquid pressure varies between a maximum and a minimum or is substantially constant. The volume of solution dispensed is varied at times when the liquid pressure is varying by selection of an aperture from a plurality of apertures at varying axial positions, for placing the interior of the pipeline in communication with the interior of the enclosure above the solution level, at times when the level drops axially to the selected aperture; or, at time when the liquid pressure is substantially constant, by adjustment of the amount of liquid permitted to enter the device.