The present invention relates to a reinforcement valve for preventing a backflow in a drain trap, which can be additionally installed inside a drain trap, which can perform the air backflow phenomenon pre-contributing to the quality of the quality of the drain trap and to performance improvement thereof, and which always has the best backflow blocking function regardless of a strong air pressure generated inside the drain trap and any change thereof. A conventional drain trap has a water gathering portion (20) formed beneath a trap body (10); an inflow-side drain tube (30) and a discharged-side drain tube (40) are connected to one side and the other side thereof, respectively, such that draining occurs therethrough; a blocking membrane (60) is configured between the water inflow opening (31) And the water discharge opening (41); and a water drain hole (51) is bored between the blocking membrane (60) and the bottom surface inside the trap body (10). Th e present invention is configured by installing a backflow-preventing reinforcement valve (100) on the front side of the blocking membrane (60), in which the water drain hole (51) is formed, such that, when water is drained from the corresponding household, the same is automatically opened by the water pressure, thereby allowing water to drain, and, when water draining is completed, the same is automatically closed by self-weight, thereby guaranteeing, through control, that, even if a strong air flow is introduced into the drain trap, no backflow of air occurs.

A liquid cleaning system rests on a surface having a non-porous material covering and a drain. A lower plate layer and an upper plate layer each have runners arranged in a grid. The lower plate layer rests upon the surface and the upper plate layer rests upon the lower plate layer offset at an angle with respect to the grid of the lower plate layer. An upper layer covers the upper plate layer and has a plurality of holes for the passage of fluids into the liquid cleaning system. As liquid enters the liquid cleaning system through the holes, the liquid traverses the grid of the lower plate layer and the grid of the upper plate layer flowing towards the drain, and contaminants within the liquid collect within the grid of the lower plate layer and the grid of the upper plate layer.

A backflow prevention apparatus is provided with a check valve and a float-type backflow prevention valve, these being installed in this order as one proceeds from upstream to downstream. The check valve comprises a valve seat; a valve member that closes the valve at the valve seat due to an upwardly directed restoring force; and a restoring force exerting member that exerts an upwardly directed restoring force on the valve member. The float-type backflow prevention valve comprises an annular valve seat; a float that rises in accompaniment to a rise in a water level of wastewater to close the valve at the annular valve seat; a guide member that guides movement of the float in a vertical direction; and a constraining member that constrains a lowermost position to which the float can move.

An odor-trap device (1) for in particular flushing-water-free sanitary devices, for example urinals, comprises an outflow element (2) with a sealing wall (3), and also comprises a sealing membrane (4), which is in sealing contact with the sealing wall (3) in a closure position and, in the presence of a liquid, such as urine, is pushed away from the sealing wall (3) from the closure position into an open position, as a result of which a gap (19) is formed between the sealing membrane (4) and sealing wall (3), it being possible for the liquid to be led away through said gap, and further comprises a mounting element (5) for mounting the sealing membrane (4) in relation to the sealing wall (3). The odor-trap device (1) is characterized in that the seating membrane (4) has a seating surface (6) which runs substantially parallel to the sealing wall (3), wherein the sealing surface (6) butts against the sealing wall (3) substantially with surface-area contact, or wherein the sealing surface (6) is spaced apart from the sealing wall (3) such that the liquid film which is present, at least in part, between the sealing wall (3) and the sealing surface (6) provides a force of adhesion between the sealing wall (3) and seating surface (6).

The present invention discloses a self-adjustable gas isolator, including a floater, a liquid storage device, a liquid outlet, a cover plate, a liquid discharging hole and a pressure balancing device. The floater has a pressure relief port; the pressure balancing device is connected with the floater in fixed position; the floater is sleeved in the liquid storage device and the floater goes up and down along with liquid level in the liquid storage device. The sealing device regulates the opening degree between the floater and the liquid outlet automatically according to the liquid volume discharged, and the pressure balancing device releases gas pressure preventing liquid from discharging, and the discharging speed of liquid is fast. The self-adjustable gas isolator is simple in structure, no components for hooking sundries in its channel, and is not easy to jam. When discharging liquid, the floater swings or rotates with self-cleaning function.

5 A liquid cleaning system rests on a surface having a non-porous material covering and a drain. A lower plate layer and an upper plate layer each have runners arranged in a grid. The lower plate layer rests upon the surface and the upper plate layer rests upon the lower plate layer offset at an angle with respect to the grid of the lower plate layer.

An upper layer covers the upper plate layer and has a plurality of holes for the passage of fluids into the liquid cleaning system. As liquid enters the liquid cleaning system through the holes, the liquid traverses the grid of the lower plate layer and the grid of the upper plate layer flowing towards the drain, and contaminants within the liquid collect within the grid of the lower plate layer and the grid of the upper plate layer.

A backflow prevention apparatus is provided with a check valve and a float-type backflow prevention valve, these being installed in this order as one proceeds from upstream to downstream. The check valve comprises a valve seat; a valve member that closes the valve at the valve seat due to an upwardly directed restoring force; and a restoring force exerting member that exerts an upwardly directed restoring force on the valve member. The float-type backflow prevention valve comprises an annular valve seat; a float that rises in accompaniment to a rise in a water level of wastewater to close the valve at the annular valve seat; a guide member that guides movement of the float in a vertical direction; and a constraining member that constrains a lowermost position to which the float can move.

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.