Abstract: There is described a water carbonation apparatus in which two carbonation units (10, 11) are linked to a volumetric control unit (9) which stores a volume of carbonated water ready for use. When carbonated water is to be discharged, the stored carbonated water from the volumetric control unit (9) is discharged, while simultaneously carbonated water from one of the carbonation units (10, 11) is discharged into the other carbonation unit (11, 10) is filled with uncarbonated water from the volumetric control unit (9), and a volume of uncarbonated water is drawn from a water supply (2) into the volumetric control unit. The volumetric control unit (9) in one embodiment comprises a pair of piston and cylinder assemblies which together define four internal chambers (21, 22, 23, 24), the pistons being linked together such that the volumes of the four internal chambers vary at the same rate.

Abstract: There is described a water carbonation apparatus in which two carbonation units (10, 11) are linked to a volumetric control unit (9) which stores a volume of carbonated water ready for use. When carbonated water is to be discharged, the stored carbonated water from the volumetric control unit (9) is discharged, while simultaneously carbonated water from one of the carbonation units (10, 11) is discharged into the other carbonation unit (11, 10) is filled with uncarbonated water from the volumetric control unit (9), and a volume of uncarbonated water is drawn from a water supply (2) into the volumetric control unit. The volumetric control unit (9) in one embodiment comprises a pair of piston and cylinder assemblies which together define four internal chambers (21, 22, 23, 24), the pistons being linked together such that the volumes of the four internal chambers vary at the same rate.