A siphon trap disinfection unit consisting of a copper/silver electrode coated on inside body of the siphon parallel to each other along the siphon in the area which water normally stands. A water level sensor to generate resistance between two electrodes and an electric controller circuit to generate ions by applying voltage between two electrodes and controlling the amount of current passing through this control circuit to generate enough concentration of copper and silver ion continuously in the water standing area of the siphon trap to remove and deactivate harmful bacteria's in this area.

A multi-layer water sealing device, includes at least two layers of water seal sequentially arranged from top to bottom. An upper-layer water seal has a floating bell-shaped cover structure, and the floating bell-shaped cover structure includes a water sealing box and a floating bell-shaped cover arranged in the water sealing box. A lower-layer water seal is arranged in a drain pipe below the floating bell-shaped cover, and one side of the water sealing box is extended to form or connected to a communication cavity offset from the drain pipe. The floating bell-shaped cover correspondingly is extended to form or connected to a floating component floatable in the communication cavity and offset from the drain pipe.

A multi-layer water sealing device, includes at least two layers of water seal sequentially arranged from top to bottom. An upper-layer water seal has a floating bell-shaped cover structure, and the floating bell-shaped cover structure includes a water sealing box and a floating bell-shaped cover arranged in the water sealing box. A lower-layer water seal is arranged in a drain pipe below the floating bell-shaped cover, and one side of the water sealing box is extended to form or connected to a communication cavity offset from the drain pipe. The floating bell-shaped cover correspondingly is extended to form or connected to a floating component floatable in the communication cavity and offset from the drain pipe.

A WC device with a WC body and a flushing water supply device for supplying flush water to the toilet body. The flush water supply device is provided with a water connection for drinking water for use as flush water. The WC body has a bowl-shaped WC body section and a subsequent odor trap. The bowl-shaped WC body section has a porous inner surface which is connected to a device for supplying cleaning fluid for keeping the porous inner surface clean. The flushing water supply device is provided with at least one back-suction safety device, which prevents back-suction of cleaning liquid from the porous inner surface to the water connection. Thus, the WC device completely or at least largely prevents excrement or dirt residues from adhering to the inner surface of the WC body, and the back-suction safety device provides hygienically flawless protection on the drinking water side.

A WC device with a WC body and a flushing water supply device for supplying flush water to the toilet body. The flush water supply device is provided with a water connection for drinking water for use as flush water. The WC body has a bowl-shaped WC body section and a subsequent odor trap. The bowl-shaped WC body section has a porous inner surface which is connected to a device for supplying cleaning fluid for keeping the porous inner surface clean. The flushing water supply device is provided with at least one back-suction safety device, which prevents back-suction of cleaning liquid from the porous inner surface to the water connection. Thus, the WC device completely or at least largely prevents excrement or dirt residues from adhering to the inner surface of the WC body, and the back-suction safety device provides hygienically flawless protection on the drinking water side.

A drain cleaning and maintenance system, including a drain trap, having a first inlet in fluid communication with a drain of a plumbing fixture, a second inlet in fluid communication with the drain trap and a cleaning and maintenance assembly. The assembly includes a maintenance-assembly inlet in fluid communication with a source of pressurized liquid, and a maintenance-assembly outlet in fluid communication with the second inlet. An electronic valve has an open state allowing flow of liquid, from the maintenance-assembly inlet to the maintenance-assembly outlet, and a closed state blocking flow of liquid from the maintenance-assembly inlet to the maintenance-assembly outlet. An electronic controller is adapted to transition the electronic valve between the open state and the closed state, to allow liquid flow from the source to the drain trap via the second inlet.

A siphon includes a feed area for feeding a liquid, a downpipe connecting to the feed area, extended from top to bottom in a use position of the siphon, a deflection pipe filled with liquid during stationary operation on the end of the downpipe facing away from the feed area connecting to this, a riser pipe on the end of the deflection pipe facing away from the downpipe, and connecting to this, extended from bottom to top in the use position, and a discharge area connecting to the end of the riser pipe facing away from the deflection pipe for discharging liquid. A storage tank arranged on the siphon between the feed area and the discharge area is hydraulically connected to the deflection pipe and designed to automatically fill with liquid during stationary operation and to automatically empty into the deflection pipe following a pressure surge affecting the siphon.

A drain structure used for mounting in a pipe includes a ring wall, a bottom plate and a chamber, wherein at least one overflow hole mounted on the ring wall communicates with an inner ring wall and an outer ring wall. The overflow hole comprises a first opening and a second opening, wherein the first opening comprises a top edge, and the second opening comprises a bottom edge. A first horizontal surface passes through the top edge of the first opening, and a second horizontal surface passes through the bottom edge of the second opening, wherein the first horizontal surface is not higher than the second horizontal surface to form a first water tank between the second horizontal surface and the bottom plate. Liquid accumulated in the first water tank is able to prevent insects and gases in outdoors from entering indoors via the pipe.

A drain structure used for mounting in a pipe includes a ring wall, a bottom plate and a chamber, wherein at least one overflow hole mounted on the ring wall communicates with an inner ring wall and an outer ring wall. The overflow hole comprises a first opening and a second opening, wherein the first opening comprises a top edge, and the second opening comprises a bottom edge. A first horizontal surface passes through the top edge of the first opening, and a second horizontal surface passes through the bottom edge of the second opening, wherein the first horizontal surface is not higher than the second horizontal surface to form a first water tank between the second horizontal surface and the bottom plate. Liquid accumulated in the first water tank is able to prevent insects and gases in outdoors from entering indoors via the pipe.

A siphon trap disinfection unit consisting of a copper/silver electrode coated on inside body of the siphon parallel to each other along the siphon in the area which water normally stands. A water level sensor to generate resistance between two electrodes and an electric controller circuit to generate ions by applying voltage between two electrodes and controlling the amount of current passing through this control circuit to generate enough concentration of copper and silver ion continuously in the water standing area of the siphon trap to remove and deactivate harmful bacteria's in this area.