A carbonator comprising a tube cylinder having a closed and an open end. A disk is removably retained in the open end for providing access into the interior volume thereof. The disk provides for mounting thereto of water and carbon dioxide gas inlets, a carbonated water outlet, a safety relief valve and a water level sensor. A rigid retaining wire is bent into a square configuration wherein radiussed corners thereof cooperate with slots in the open end of the cylinder to retain the disk therein. Manipulation of the retaining wire provides for removal of the disk from the cylinder when the carbonator is not pressurized.