Abstract: A check valve includes an elongated housing having an inlet port at the upper end and an outlet port at a lower end and a float movable therein. An exterior valve seat surrounds the outlet and a valve stem connected to the float extends through the outlet port and has a valve element on the outer end which cooperates with the valve seat.

Abstract: A germicidal periodontal irrigation system employs a stream of irrigating liquid in which bubbles of ultraviolet-produced ozone are finely dispersed. The flow of irrigating liquid through an irrigation conduit carries the ozone bubbles to the inflamed areas to effect a germicidal action. Ozonation of the carrier liquid is produced by passing a gas containing oxygen in the immediate vicinity of an irradiating ultraviolet lamp to produce "actinic" ozone, the gas then being bubbled through a storage reservoir from which the irrigating liquid is continuously drained and dispensed, carrying the ozone bubbles along with it. Alternatively, the ozonated gas is injected directly into the irrigation conduit to form a stream of finely-dispersed bubbles in the flowing liquid. The irrigating stream is preferably dispensed in the form of a high-pressure pulsating jet of liquid injected at the gum line to provide a high local concentration of ozone for germicidal treatment.

Abstract: A bottle rack includes a vertical support member supported on a pair of spaced parallel mounting members and a bottle engaging arm that extends outwardly from the support member at an acute angle of about 20.degree. to about 50.degree. with indentations in the arm to receive the necks of bottles so that indicia on the bottles is in full view to the user of the rack.

Abstract: A batch water treatment system is provided in which ozone is the reactive agent. The system includes a holding tank containing untreated water in communication with a reaction tank in which ozone is dispersed under pressure through a plurality of foraminous diffusers which are connected to a modular ozone generator. Impurities contained in the water are oxidized or broken down by the ozone into forms capable of filtration, and as this treatment process progresses the water is circulated through a conduit to a monitor which measures the level of impurities in the water. Once a predetermined proportion of impurities are broken down and filtered from the system, the monitor automatically activates a drain line to evacuate the reaction tank of the treated water and then refills it with more untreated water from the holding tank to repeat the process.