Abstract: A method and apparatus for providing a disinfectant cycle of a medical device such as a dental device having an input water line with a main valve and a plurality of water lines extending to instruments with control valves characterized by an arrangement for injecting a disinfectant into the input line downstream of the main valve and an arrangement for controlling the opening and closing of the various valves to enable replacing the water in the water lines with disinfectant, and subsequently flushing the disinfectant therefrom. The method and apparatus can include a device for dosing the water flowing through the water lines during usage with a disinfectant to retard growth of microorganisms and the apparatus can include a selector switch to select various modes of operation.

Abstract: An improved double wall hose and the method of forming the hose characterized by the hose comprising a helically wound member having a center part with extensions extending in opposite directions so that when adjacent turns of the member are joined together, a plurality of cavities are formed with one of the cavities containing a helical reinforcing member. Preferably, the reinforcement is of a material harder than the material forming the rest of the member and the turns of the member when joined together provide smooth continuous inner and outer wall surfaces for the hose.