Patent Publication Number: US-2022220717-A1

Title: Flush toilet

Description:
The invention relates to the field of gravity-powered toilets for removal of human and other waste. In certain embodiments, the invention relates to gravity-powered toilets having a tank configured to be installed within a room wall, or an “in-wall” tank. 
     BACKGROUND 
     Space is becoming more valuable in bathrooms, particularly with a current world-wide shift in population toward urban centers having smaller living spaces. Typically, the space taken up by a toilet includes a bowl, trapway and tank. The tank is usually positioned over the back of the bowl. The tank and bowl can be separate pieces which are coupled together to form a toilet system, or can be one integral unit. 
     The tank contains water used for initiating flushing of waste from the bowl to a sewage line and for refilling the bowl with fresh water. When a user desires to flush the toilet, the user may push a flush lever located on the outside of the tank, which is connected on the inside of the tank to a moveable chain or lever. The chain or lever acts to open a flush valve, causing water to flow from the tank and into the bowl, initiating a toilet flush. 
     There are three general purposes to be accomplished in a flush cycle. The first is the removal of solid and/or other waste to the drain line. The second is cleansing of the bowl to remove any solid or liquid waste which was deposited or adhered to the surfaces of the bowl, and the third is exchanging the pre-flush water volume in the bowl so that relatively clean water remains in the bowl between uses. The second requirement, cleansing of the bowl, may be achieved by way of a hollow rim that extends around the upper perimeter of the toilet bowl. Some or all of the flush water is directed through this rim channel and flows through openings positioned therein to disperse water over the entire surface of the bowl and accomplish the desired cleansing. The third requirement is to refill the bowl with clean water, restoring the seal depth against backflow of sewer gas, and readying it for the next usage and flush. 
     Gravity-powered toilets fall generally into two categories: wash-down and siphonic. In a wash-down toilet, the water level within the bowl of the toilet remains relatively constant at all times. When a flush cycle is initiated, water flows from the tank and spills into the bowl. This causes a rapid rise in water level and the excess water spills over the weir of the trapway, carrying liquid and solid waste along with it. At the conclusion of the flush cycle, the water level in the bowl naturally returns to the equilibrium level determined by the height of the weir. 
     In a siphonic toilet, the trapway and other hydraulic channels are designed such that a siphon is initiated in the trapway upon addition of water to the bowl. The siphon tube itself is an upside down curved, generally U-shaped tube that draws water from the toilet bowl to the wastewater line. When the flush cycle is initiated, water flows into the bowl and spills over the weir in the trapway faster than it can exit the outlet to the sewer line. Sufficient air is eventually removed from a down leg of the trapway to initiate a siphon, which in turn pulls the remaining water by vacuum out of the bowl. The water level in the bowl when the siphon breaks is consequently well below the level of the weir, and a separate mechanism needs to be provided to refill the bowl of the toilet at the end of a siphonic flush cycle to reestablish the original water level and protective “seal” against back flow of sewer gas. 
     Siphonic and wash-down toilets have inherent advantages and disadvantages. Siphonic toilets, due to the requirement that most of the air be removed from the down leg of the trapway in order to initiate a siphon, tend to have smaller trapways which can result in clogging. Wash-down toilets can function with large trapways but generally require a smaller amount of pre-flush water in the bowl to achieve the 100:1 dilution level required by plumbing codes in most countries (i.e., 99% of the pre-flush water volume in the bowl must be removed from the bowl and replaced with fresh water during the flush cycle). This small pre-flush volume manifests itself as a small “water spot.” The water spot, or surface area of the pre-flush water in the bowl, plays an important role in maintaining the cleanliness of a toilet. A large water spot increases the probability that waste matter will contact water before contacting the ceramic surface of the toilet. This reduces adhesion of waste matter to the ceramic surface making it easier for the toilet to clean itself via the flush cycle. Wash-down toilets having smaller water spots therefore require more frequent manual cleaning of the bowl after use. 
     Siphonic toilets have the advantage of being able to function with a greater pre-flush water volume in the bowl and a greater water spot. This is possible because the siphon action pulls the majority of the pre-flush water volume from the bowl at the end of the flush cycle. As the tank refills, a portion of the refill water can be directed into the bowl to return the pre-flush water volume to its original level. In this manner, the 100:1 dilution level required by many plumbing codes is achieved even though the starting volume of water in the bowl is significantly greater relative to the flush water exited from the tank. In the North American markets, siphonic toilets have gained widespread acceptance and are now viewed as the standard, accepted form of toilet. In European markets, wash-down toilets are still more accepted and popular, whereas both versions are common in the Asian markets. 
     As described in US2010/0043130 and US2016/0002903, gravity-powered siphonic toilets generally fall into three categories, depending on the design of the hydraulic channels used to achieve the flushing action. These categories are: non-jetted, rim jetted, and direct jetted. 
     In non-jetted bowls, all of the flush water exits the tank and flows through a manifold into a rim channel of the bowl. The water is dispersed around the perimeter of the bowl via a series of holes positioned underneath the rim. Some of the holes may be designed to be larger in size to allow greater flow of water into the bowl. A relatively high flow rate is needed to spill water over the weir of the trapway rapidly enough to displace sufficient air in the down leg and initiate the siphon. Non-jetted bowls typically have adequate to good performance with respect to cleansing of the bowl and replenishment of the pre-flush water, but are relatively poor in performance in terms of bulk removal. The feed of water to the trapway is inefficient and turbulent, which makes it more difficult to sufficiently fill the down leg of the trapway and initiate a strong siphon. Consequently, the trapway of a non-jetted toilet is typically smaller in diameter and contains bends and constrictions designed to impede flow of water. Without the smaller size, bends, and constrictions, a strong siphon would not be achieved. Unfortunately, the smaller size, bends, and constrictions result in poor performance in terms of bulk waste removal and frequent clogging, conditions that are extremely dissatisfying to end users. 
     Designers and engineers of toilets have improved the bulk waste removal of siphonic toilets by incorporating “jets.” In a rim-jetted toilet bowl, flush water exits the tank and flows through a manifold into the rim channel. A portion of the water is dispersed around the perimeter of the bowl via a series of holes positioned underneath the rim. The remaining portion of water flows through a jet channel positioned at the front of the rim. This jet channel connects the rim channel to a jet opening positioned in the sump of the bowl. The jet opening is sized and positioned to send a powerful stream of water directly at the opening of the trapway. When water flows through the jet opening, it serves to fill the trapway more efficiently and rapidly than can be achieved in a non-jetted bowl. This more energetic and rapid flow of water to the trapway enables toilets to be designed with larger trapway diameters and fewer bends and constrictions, which, in turn, improves the performance in bulk waste removal relative to non-jetted bowls. Although a smaller volume of water flows out of the rim of a rim-jetted toilet, the bowl cleansing function is generally acceptable as the water that flows through the rim channel is pressurized. This allows the water to exit the rim holes with higher energy and do a more effective job of cleansing the bowl. 
     Although rim-jetted bowls are generally superior to non-jetted, the long pathway that the water must travel through the rim to the jet opening dissipates and wastes much of the available energy. Direct-jetted bowls improve on this concept and can deliver even greater performance in terms of bulk removal of waste. In a direct-jetted bowl, the flush water exits the tank and flows through a manifold. At this point, the water is divided into two portions: a portion that flows through the rim channel with the primary purpose of achieving the desired bowl cleansing, and a portion that flows through a second “direct jet channel” that connects the manifold to a jet opening in the sump of the toilet bowl. The direct jet channel can take different forms, sometimes being unidirectional around one side of the toilet, or being “dual fed,” wherein symmetrical channels travel down both sides connecting the manifold to the jet opening. As with the rim-jetted bowls, the jet opening is sized and positioned to send a powerful stream of water directly at the opening of the trapway. When water flows through the jet opening, it serves to fill the trapway more efficiently and rapidly than can be achieved in a non-jetted or rim jetted bowl. This more energetic and rapid flow of water to the trapway enables toilets to be designed with even larger trapway diameters and minimal bends and constrictions, which, in turn, improves the performance in bulk waste removal relative to non-jetted and rim jetted bowls. 
     A need remains to provide a high-performance toilet that takes up less space in a bathroom. 
     SUMMARY 
     Accordingly, disclosed is a siphonic flush toilet system, the system comprising a bowl, a tank, and a rim flush valve assembly and/or a jet flush valve assembly, wherein the bowl comprises a rim extending at least partially around a bowl upper perimeter; an interior surface and an exterior surface; a wall defining the interior surface and exterior surface; and a sump area; the tank comprises an interior space configured to hold fluid; and a height, a width, and a depth, based on a tank exterior, wherein the height is from about 17.0 inches to about 29.0 inches; the width is from about 10.5 inches to about 18.5 inches; and he depth is from about 3.10 inches to about 3.60 inches; and the flush valve assembly comprises a flush valve body extending from a flush valve inlet to a flush valve outlet; a flapper cover having a top face and a bottom face and a front and a back; and a flush actuator comprising a lift rod; wherein the sump area is configured to be in fluid communication with a trapway inlet; the flush valve assembly is positioned in the interior space of the tank; the bottom face of the flapper cover is configured to enclose the flush valve inlet; and the lift rod is coupled to the top face of the flapper cover and is configured to lift the flapper cover to open the flush valve. 
     Also disclosed is a flush toilet system comprising a bowl, a tank, a rim flush valve assembly and/or a jet flush valve assembly, an overflow tube, and a rim conduit and/or a jet conduit, wherein the flush valve assembly is positioned in an interior space of the tank; the flush valve assembly comprises a flush valve body extending from a flush valve inlet to a flush valve outlet; the conduit is in fluid communication with the flush valve outlet and a rim inlet port or a jet inlet port; and wherein the overflow tube is coupled to and in fluid communication with the conduit. 
     Also disclosed is a toilet tank assembly for a siphonic flush toilet system, the tank comprising an interior space configured to hold fluid; and a height, a width, and a depth, based on a tank exterior, wherein the height is from about 17.0 inches to about 29.0 inches; the width is from about 10.5 inches to about 18.5 inches; and he depth is from about 3.10 inches to about 3.60 inches. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure described herein is illustrated by way of example and not by way of limitation in the accompanying figures. For simplicity and clarity, features illustrated in the figures are not necessarily drawn to scale. For example, dimensions of some features may be exaggerated relative to other features for clarity. Further, where considered appropriate, reference labels have been repeated among the figures to indicate corresponding or analogous elements. 
         FIG. 1A  depicts a top perspective view of a flush valve assembly according to an embodiment. 
         FIG. 1B  depicts a cut-away side view of a flush valve assembly according to an embodiment. 
         FIG. 2  represents an embodiment of a flush valve assembly associated with a hydraulic cylinder. 
         FIG. 3A ,  FIG. 3B  and  FIG. 3C  show an elliptical flush valve body according to an embodiment, in a perspective view, top view and side view, respectively. 
         FIG. 4  depicts a side cut-away view of a flush valve body containing a lead-in lip, according to an embodiment. 
         FIG. 5A  and  FIG. 5B  depict a side view and top view of a flush valve body, respectively, containing a lead-in lip, according to an embodiment. 
         FIG. 6A  and  FIG. 6B  show a toilet tank assembly according to an embodiment. 
         FIG. 6C ,  FIG. 6D ,  FIG. 6E , and  FIG. 6F  show a flush valve assembly from left side, right side, back, and front views, respectively, according to an embodiment. 
         FIG. 6G ,  FIG. 6H , and  FIG. 6I  show a cross-section view of a flush valve in various stages of valve opening, according to an embodiment. 
         FIG. 7  shows a toilet tank assembly according to an embodiment. 
         FIG. 8A  and  FIG. 8B  depict a toilet bowl, according to some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     The toilet bowl comprises a rim extending at least partially around an upper perimeter of the bowl, an interior surface, an exterior surface, a wall defining the interior and exterior surfaces, and a sump area. 
     The toilet bowl assembly may, in one embodiment further comprise a rim conduit, wherein the rim conduit has a rim conduit inlet opening for receiving fluid from the outlet of a rim flush valve assembly and a rim conduit outlet opening for delivery of fluid to a rim inlet port. The bowl may comprise a rim that extends at least partially around an upper perimeter of the bowl, the rim defining a rim channel extending from the rim inlet port around the upper perimeter of the bowl and having at least one rim outlet port in fluid communication with an interior area of the bowl, and wherein the rim inlet port is in fluid communication with the rim conduit outlet opening. 
     In another embodiment of the assembly, the bowl may have a rim that comprises a rim shelf extending transversely along an interior surface of the bowl in an upper perimeter area thereof from the rim inlet port at least partially around the bowl so that fluid is able to travel along the rim shelf and enter the interior space of the bowl in at least one location displaced from the rim inlet port. 
     The sump area is in fluid communication with a trapway inlet. In some embodiments, a portion of an interior wall of the toilet bowl in the sump area may be configured to upwardly incline from the jet outlet port toward the inlet of the trapway. 
     The sump area of the bowl in one embodiment has a jet trap defined by the interior surface of the bowl and having an inlet end and an outlet end, wherein the inlet end of the jet trap receives fluid from the jet outlet port and/or the interior area of the bowl and the outlet end of the jet trap is in fluid communication with the trapway inlet; and wherein the jet trap has a seal depth. An upper surface or uppermost point of the jet outlet port may be within the jet trap and positioned at a seal depth below an upper surface of the inlet to the trapway as measured longitudinally through the sump area. In some embodiments, a jet trap seal depth may be from any of about 1 cm, about 2 cm, about 3 cm, about 4 cm or about 5 cm to any of about 6 cm, about 7 cm, about 8 cm, about 9 cm, about 10 cm, about 11 cm, about 12 cm, about 13 cm, about 14 cm or about 15 cm or more. 
     In some embodiments, the bowl is a wall-hung bowl, supported by a bathroom wall without any floor support. In other embodiments, the bowl may be coupled to a lower toilet section configured to be supported by a bathroom floor. 
     The toilet tank comprises an interior space configured to hold fluid. The toilet tank may comprise a rectangular box-like shape, having a height, a width, and a depth, based on a tank exterior, wherein the height is from any of about 17.0 inches, about 17.5 inches, about 18.0, inches, about 18.5 inches, about 19.0 inches, about 19.5 inches, about 20.0 inches, about 20.5 inches, or about 21.0 inches, to any of about 21.5 inches, about 22.0 inches, about 22.5 inches, about 23.0 inches, about 23.5 inches, about 24.0 inches, about 24.5 inches, about 25.0 inches, about 25.5 inches, about 26.0 inches, about 26.5 inches, about 27.0 inches, about 27.5 inches, about 28.0 inches, about 28.5 inches, about 29.0 inches, or more; the width is from any of about 10.5 inches, about 11.0 inches, about 11.5 inches, about 12.0 inches, about 12.5 inches, about 13.0 inches, or about 13.5 inches, to any of about 14.0 inches, about 14.5 inches, about 15.0 inches, about 15.5 inches, about 16.0 inches, about 16.5 inches, about 17.0 inches, about 17.5 inches, about 18.0 inches, or about 18.5 inches, or more; and he depth is from any of about 3.10 inches, about 3.13 inches, about 3.16 inches, about 3.19 inches, about 3.22 inches, about 3.25 inches, about 3.27 inches, about 3.29 inches, about 3.31 inches, about 3.33 inches, about 3.35 inches, about 3.37 inches, about 3.39 inches, about 3.41 inches or about 3.43 inches to any of about 3.45 inches, about 3.47 inches, about 3.48 inches, about 3.49 inches, about 3.50 inches, about 3.51 inches, about 3.52 inches, about 3.53 inches, about 3.54 inches, about 3.55 inches, about 3.56 inches, about 3.57 inches, about 3.58 inches, about 3.59 inches, about 3.60 inches or more; The toilet tank is configured to fit behind a bathroom wall, that is within a cavity between walls (wall cavity), and to not be visible once installation is complete. 
     The walls of the toilet tank may have a thickness of from any of about 0.18 inches, about 0.19 inches, about 0.20 inches, about 0.21 inches, or about 0.22 inches, to an of about 0.23 inches, about 0.24 inches, about 0.25 inches, about 0.27 inches, about 0.28 inches, about 0.29 inches, about 0.30 inches, about 0.31 inches, or about 0.32 inches or more. 
     In some embodiments, a toilet tank, when filled with water, may comprise water at a level of about 16 inches from a tank interior bottom floor, which may be just below an overflow tube upper opening. 
     The toilet tank is configured for receiving fluid from a fluid source, the tank containing at least one fill valve. In some embodiments, the tank may include at least one jet reservoir and at least one a rim reservoir, the jet reservoir comprising a jet fill valve and at least one jet flush valve assembly, and the rim reservoir comprising at least one rim valve. In such an embodiment, the rim reservoir may further comprise a rim fill valve, the rim valve is a rim flush valve assembly and the rim flush valve assembly comprises an overflow tube. 
     The trapway comprises a weir, a trapway inlet configured to be in fluid communication with the sump area and trapway outlet configured to be in fluid communication with an outgoing sewer line. A trapway may be a ceramic material as is the bowl, or may comprise a different material, for instance a thermoplastic such as PVC or a polyolefin. 
     In some embodiments, the trapway inlet will be in a bathroom. In some embodiments, a portion of the trapway will exit the bathroom through a bathroom wall into a wall cavity, re-enter the bathroom, and exit the bathroom into the wall cavity again. In some embodiments, the trapway outlet will be in a wall cavity. In such embodiments, two separate portions of the trapway are configured to be inside a bathroom wall cavity upon installation of the system. 
     The flush valve assembly components may be formed of a polymeric material, such as a moldable thermoplastic. The flush valve body is constructed to have an interior surface that defines a flow path from an upper inlet end to a lower outlet end thereby allowing flush water to pass through the flush valve when open. 
     The flush valve comprises a flush valve body defining an interior flow path extending from a valve inlet to a valve outlet. Fluid may flow through the valve from inlet to outlet when the valve is open; fluid may not flow through the valve when the valve is closed. The flapper cover may have a generally planar shape, having a top face and a bottom face. The flapper bottom face encloses and is in contact with the valve inlet in a closed position. In a closed position, the flapper cover provides a seal so as to not allow any fluid flow through the valve. The seal is where a flapper cover bottom face is in contact with a flush valve inlet in a closed position. The seal may also be called a “sealing surface” and will have a shape corresponding to the flush valve inlet shape. 
     In some embodiments, the flapper cover is coupled to a flush actuator which comprises a lift rod. In some embodiments, the lift rod is configured to partially lift the flapper cover in order to partially open the flush valve. The lift rod may also configured to fully lift the flapper cover in order to fully open the flush valve. The term “partially lift” or “partially open” means that part of the flapper cover is lifted away from the valve inlet while part of the flapper cover remains in contact with the valve inlet. The term “fully lift” or “fully open” means that the flapper cover is completely removed from and not in contact the valve inlet. In some embodiments, the lift rod may be rigid. In other embodiments, the lift rod may be flexible or partly flexible. Upon opening of the flush valve, fluid is discharged from the tank to the bowl. 
     In some embodiments, after a partial opening of the flush valve, the lift rod may be configured to lower the flapper cover directly to the closed position to close the valve. In some embodiments, after a partial opening of the flush valve, the lift rod may be configured to further lift the flapper cover so that the valve is fully opened. Accordingly, the present assembly may provide multiple toilet flush volumes. Multiple flush volumes may correspond to a flapper cover “partial lift” and “full lift”. An operator may choose for instance a “full flush” of about 1.6 gallons (about 6 liters) of water to eliminate solid waste or a “partial flush” (short flush) of a lower volume or water, for example about 1.1 gallons (about 4 liters), for the removal of liquid waste. Multiple flush volumes are described for example in US2010/0043130. In some embodiments, a present system may be configured to provide an efficient flush with ≤about 4.0 lpf, about 4.2 lpf, about 4.4 lpf, about 4.6 lpf, about 4.8 lpf, or about 5.0 lpf (liters per flush, or per flush cycle). 
     In some embodiments, a jet flush valve may be configured to deliver from any of about 4.5 lps (liters per second), about 4.6 lps, about 4.7 lps, about 4.8 lps, about 4.9 lps, or about 5.0 lps, to any of about 5.1 lps, about 5.2 lps, about 5.3 lps, about 5.4 lps, about 5.5 lps, about 5.6 lps, about 5.7 lps, about 5.8 lps, about 5.9 lps, about 6.0 lps, or more. In some embodiments, a rim flush valve may be configured to deliver from any of about 25%, about 26%, about 27%, about 28%, or about 29%, to about 30%, about 31%, about 32%, about 33%, about 34%, about 35%, about 36%, about 37%, about 38%, about 39%, about 40%, or more, of liters per second fluid of that of a jet flush valve. In some embodiments, a rim flush valve may be configured to deliver from any of about 0.9 lps (liters per second), about 1.0 lps, about 1.1 lps, about 1.2 lps, about 1.3 lps, or about 1.4 lps, to any of about 1.5 lps, about 1.6 lps, about 1.7 lps, about 1.8 lps, about 1.9 lps, about 2.0 lps, about 2.1 lps, or more. 
     After a flapper cover is fully lifted off the valve inlet, the lift rod may be configured to further lift the flapper cover to provide more “head space” above the open inlet to provide for a greater fluid flow into the inlet. In some embodiments, the flapper cover may be lifted to a position where it is substantially parallel to the flush valve inlet and substantially perpendicular to the lift rod. In this embodiment, a substantially symmetrical, full cylinder-shaped head space above the inlet may be provided. In some embodiments, the distance of the flapper cover closed position to a position wherein it is substantially parallel to the valve inlet is from any of about 2.5 cm, about 2.6 cm, about 2.7 cm, about 2.8 cm, about 2.9 cm, about 3.0 cm, about 3.1 cm, about 3.2 cm, about 3.3 cm, about 3.4 cm, about 3.5 cm, about 3.6 cm, about 3.7 cm or about 3.8 cm to any of about 3.9 cm, about 4.0 cm, about 4.1 cm, about 4.2 cm, about 4.3 cm, about 4.4 cm, about 4.5 cm, about 4.6 cm, about 4.7 cm, about 4.8 cm, about 4.9 cm, about 5.0 cm, about 5.1 cm, about 5.2 cm, or more. 
     In some embodiments, a length of a lift rod may be from any of about 10 cm, about 12 cm, about 14 cm, about 16 cm or about 18 cm to any of about 20 cm, about 22 cm, about 24 cm, about 26 cm, about 28 cm or about 30 cm. In some embodiments, a lift rod may have a width of from any of about 0.5 cm, about 0.7 cm, about 0.9 cm, about 1.1 cm, about 1.3 cm or about 1.5 cm to any of about 1.7 cm, about 1.9 cm, about 2.1 cm, about 2.3 cm, about 2.5 cm, about 2.7 cm, or more. 
     In certain embodiments, a flush valve body may extend from a flush valve inlet to a flush valve outlet a distance of from any of about 3 cm, about 4 cm, about 5 cm or about 6 cm to any of about 7 cm, about 8 cm, about 9 cm, about 10 cm, about 11 cm, or more. 
     In some embodiments, the flapper cover may be adapted to be a “peelable” or “peel-away” cover. The flapper cover may be configured to open (lift) from the front of the cover along the edge towards the back of the cover in a peeling fashion. A peel-away flapper cover may be flexible, that is, the cover may comprise a flexible portion. A flexible flapper cover may comprise a flexible portion and a rigid portion. In some embodiments, a flapper cover flexible portion comprises an elastomer, rubber, silicone or other flexible polymer. The term “flexible” encompasses “partly-flexible”. In some embodiments, the bottom face of the flapper cover consists essentially of a flexible portion. In some embodiments, the flapper cover may comprise a continuous flexible bottom face and a top face comprising a rigid plate or plates. Rigid plates may be segmented or discontinuous. In other embodiments, the flapper cover may comprise a front flexible portion and a back rigid portion. Peelable flapper covers are described for example in US2015/0197928, US2019/0071857, and US2019/0153715. In some embodiments, when a flapper cover is partially lifted to partially open the flush valve, the valve may be considered “partially peeled open” or the flapper cover may be considered “partially peeled off” the valve inlet. 
     In some embodiments, a flapper cover may be substantially planar. In some embodiments, a peelable flapper cover may be substantially planar when in a closed position. In a process of opening, a peelable flapper may be “bent” or “curved”, and may return to a substantially planar shape in a fully open position. A present flapper cover may comprise no bulb coupled to a bottom or top face. 
     In some embodiments, a partial flapper cover lift may mean that about 50% of the flapper cover bottom face is lifted off the valve inlet from the front towards the back and about 50% of the flapper cover bottom face remains seated on the valve inlet with a partial seal intact. This refers to the diameter of the flapper cover bottom face from front to back. In other embodiments, a partial flapper cover lift may mean about 80%, about 75%, about 70%, about 65%, about 60%, about 55%, about 45%, about 40%, about 35%, about 30%, about 25% or about 20% of the flapper cover bottom face is lifted off the valve inlet from front to back with the remainder of the bottom face remaining seated on the valve inlet with a partial seal intact. 
     In certain embodiments, a flush valve inlet is non-circular. A circular valve inlet has an inlet which is circular from a top view (like the top view of a cylinder), that is to say, the seal of a closed valve is circular. In some embodiments, a non-circular valve inlet may be elliptical. Flush valves having non-circular valve inlets may have circular or non-circular outlets and/or circular or non-circular bodies. Flush valves having non-circular valve inlets may have correspondingly non-circular shaped flapper covers. 
     In certain embodiments, non-circular flush valve inlet shapes may include triangular, rectangular, square, oval, oblong, ovate, elliptic (elliptical), obovate, cuneate, deltoid and orbicular, among others. Flapper covers may have corresponding shapes configured to form a seal when placed over a flush valve inlet with the valve in a closed position. Triangular and rectangular shapes include those having one or more rounded angles. 
     In some embodiments, an area of a flush valve inlet may be from any of about 45 cm 2 , about 47 cm 2 , about 50 cm 2 , about 53 cm 2  or about 56 cm 2  to any of about 59 cm 2 , about 62 cm 2 , about 65 cm 2 , about 68 cm 2 , about 71 cm 2 , about 74 cm 2 , about 77 cm 2  or about 80 cm 2 . A flush valve inlet area may be measured at a highest plane of an inlet. A surface area of a flapper cover bottom or top face may have slightly larger surface areas or about the same or similar surface areas. 
     In some embodiments, the flush valve assembly may comprise a back-flow preventer mechanism, for example a back-flow preventer mechanism as described in US2015/0197928. Back-flow preventer mechanisms include hold-down linkage mechanisms, hook and catch mechanisms, poppet mechanisms, and check valves. An advantage of the present flush valve assembly is that a back-flow preventer mechanism may not be required as the lift rod itself may hold the flapper cover in a closed position and prevent any back-flow. 
     The flush valve assembly may be associated with other elements, for instance an overflow tube, a fill valve, a float, a cleaning injection system, and the like. 
     A flush actuator comprising a lift rod, which may be associated with a motor, for instance an electric gear motor, a hydraulic cylinder, a pneumatic cylinder, a piston, a manual lever, a push button, or a combination thereof. The present flapper covers may be lifted from the front towards the back, for instance in a peelable fashion. Thus, the flush valve assemblies require less energy to lift and open the flapper cover, allowing the elements of the assemblies to undergo less stress and allowing them to last longer. 
     A tank may be associated with a panel visible from and accessible in the bathroom wall. The panel may comprise one or more push buttons for actuation of the flush assembly. For instance, a panel may comprise a push button for a partial flush and a separate push button for a full flush. The one or more buttons may be associated with an electric motor, a hydraulic cylinder, a pneumatic cylinder, a piston, a manual lever or a combination thereof. The panel may also comprise a power source, for instance a battery or direct wiring. A toilet tank may have a window configured for installation of a panel. 
     A flush actuation assembly may comprise a flush actuator and associated means of initiating actuation, for instance an electric motor, power source, push button(s), panel, etc. 
     In some embodiments, a system comprising rim flush valve and a jet flush valve may comprise a flush actuation assembly comprising a flush activation bar comprising a first section connected to a rim flush valve assembly and a second section connected to a jet flush valve assembly. A flush activation bar may be coupled to a pivot rod. A pivot rod may be associated with and in electric and/or manual communication with for example an electric motor, a hydraulic cylinder, a pneumatic cylinder, a piston, a manual handle, etc. 
     In some embodiments, the fluid flow path from flush valve body inlet to outlet is uniform, that is, the interior shape of the valve inlet body from inlet to outlet, defining the flow path, is uniform. In other embodiments, an inlet may be “radiused” or “curved”, for example comprise a “lead-in angle”. In some embodiments, a portion of the flush valve body may be downwardly-tapered from inlet to outlet, providing a decreasing valve body diameter along the flow path, that is, providing a decreasing liquid volume flow path (decreasing flow path). In some embodiments, a flush valve body may comprise both a radiused inlet and a downwardly-tapered valve body. The terms “radiused” and “downwardly-tapered” may mean linearly radiused or tapered or, may mean non-linearly radiused or tapered. Flush valves having a radiused inlet and tapered bodies are described for example in U.S. Pat. Nos. 6,715,162, 6,728,975 and 6,901,610, and U.S. Pub. No. 2014/0090158. 
     In some embodiments, a flush valve body that is downwardly-tapered may be generally symmetrical, providing a generally symmetrical decreasing flow path. In other embodiments, a flush valve body that is downwardly-tapered may be non-symmetrical, providing a non-symmetrical decreasing flow path. A flush valve body will also have a front and a back, corresponding to front and a back sections of a flapper cover. Non-symmetrical tapering may mean a flush valve body front or back is more tapered than the other. Non-symmetrical tapering may mean a liquid flow path is longer in a flush valve body front or back than the other. Another way to describe a non-symmetrical downwardly-tapered flush valve body is that a valve outlet center is not aligned with a valve inlet center along an x-y plane or along an x-z plane. A “center” means a mid-point along a longest diameter. A non-symmetrical flush valve body may be linearly or non-linearly downwardly-tapered. In some embodiments, a non-symmetrical flush valve body may comprise a circular or a non-circular inlet. 
     A non-symmetrical flush valve body may comprise a symmetrical portion and a non-symmetrical portion. For instance, a flush valve body may comprise a symmetrical, substantially circular (substantially cylindrical) outlet portion and a non-symmetrical downwardly-tapered inlet portion. 
     In some embodiments, a flush valve assembly comprises a flush valve body extending from a flush valve inlet to a flush valve outlet, wherein the flush valve inlet comprises a lead-in lip. A “lead-in lip” may be described as an inverted geometry on the outside of the sealing surface. A lead-in lip may help direct the flow of water up and over a flush valve inlet. 
     In some embodiments, a lead-in lip may extend downward from any of about 5%, about 7%, about 9%, about 11%, about 13%, about 15%, about 17%, or about 19%, to any of about 21%, about 23%, about 25%, about 27%, about 29%, about 31%, or more, of the distance from a valve inlet to a valve outlet. 
     In some embodiments, a lead-in lip may extend downward from any of about 4.0 mm, about 4.5 mm, about 5.0 mm, about 5.5 mm, about 6.0 mm, about 6.5 mm, or about 7.0 mm, to any of about 7.5 mm, about 8.0 mm about 8.5 mm, about 9.0 mm, about 9.5 mm, about 10.0 mm, about 10.5 mm, about 11.0 mm, about 11.5 mm, about 12.0 mm, about 12.5 mm, about 13.0 mm, about 13.5 mm, about 14.0 mm, about 14.5 mm, about 15.0 mm, about 15.5 mm, or more, from a valve inlet (from a top point of a valve inlet). 
     In some embodiments, a lead-in lip may extend around an entirety of a valve inlet. In other embodiments, a lead-in lip may extend partly around a valve inlet, for instance around about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, about 90%, or about 95% of the perimeter of a valve inlet. 
     In some embodiments, an area of a flush valve outlet may be the same or similar to a flush valve inlet. In other embodiments, an area of a flush valve outlet may be smaller than that of a flush valve inlet, for instance if the valve body is downwardly-tapered. For instance, in some embodiments, an area of a flush valve outlet may be from any of about 8 cm 2 , about 9 cm 2 , 10 cm 2 , about 12 cm 2 , about 14 cm 2 , about 16 cm 2  or about 18 cm 2  to any of about 20 cm 2 , about 22 cm 2 , about 24 cm 2 , about 26 cm 2 , about 28 cm 2 , about 30 cm 2  or about 32 cm 2  (internal cross-sectional area). 
     In some embodiments, a tank is configured to hold from any of about 2.2 gallons, about 2.4 gallons, about 2.6 gallons, about 2.8 gallons, or about 3.0 gallons, to any of about 3.2 gallons, about 3.4 gallons, about 3.6 gallons, about 3.8 gallons, or more, prior to initiation of a flush cycle. 
     Flush valve assemblies having a flush valve having a circular inlet may in general also comprise a circular-shaped flapper cover. Flush valve assemblies having a flush valve having a non-circular shaped inlet may in general also comprise a correspondingly non-circular shaped flapper cover. For instance, a flush valve assembly having a flush valve having an elliptical valve inlet may comprise an elliptical flapper cover. As discussed, in some embodiments, the flapper cover is configured to lift and open the valve from the front of the cover towards the flapper cover back. The flapper cover comprises a front section (the front) and a back section (the back), which sections meet at an arbitrary point along a diameter of the flapper cover. The arbitrary point may be at a point midway along a diameter, or at any point along a diameter or at any line bisecting the flapper cover. A flush valve body will have corresponding front and back sections. 
     In some embodiments, a present flapper cover having a triangular, ovate, obovate, cuneate or deltoid or similar shape, will comprise a narrow end and a wide end. In some embodiments, a flapper cover front will comprise the narrow end and a flapper cover back will comprise the wide end. In other embodiments, a flapper cover front will comprise the wide end and a flapper cover back will comprise the narrow end. 
     In certain embodiments, the flapper cover may by be coupled to the lift rod via hinged arms disposed on the top face. Hinged arms may be adapted to provide a peelable flapper cover. Hinged arms disposed on a flapper cover are described in US2015/0197928. 
     In other embodiments, the flapper cover may be coupled to the lift rod via a multi-arm linkage. In some embodiments a lift rod and/or a multi-arm linkage may comprise a rigid material, for instance a thermoplastic. The flush actuator may comprise no chain or chains. In an embodiment, a multi-arm linkage comprises a pivot arm coupled to the flapper cover top face towards the flapper front. In some examples, the pivot arm is curved. In certain embodiments, the pivot arm may be curved inward toward the flapper cover center. A flapper cover “center” means a mid-point along a diameter, for instance along a longest diameter. The pivot arm may also comprise one or more joints around which the arm may rotate or flex. A multi-arm linkage may comprise one or more slotted elements adapted to allow movement of other elements, for example sliding or flex motion of one or more arms when a flapper cover is in motion—that is, being lifted or lowered. The slotted elements may aid in a flapper cover lifting, lowering, and/or a peeling motion. Elements may be coupled to slotted elements via a slot-and-pin arrangement. Slot-and-pin attachments allow for movement of the pin within the slot. 
     The pivot arm may be coupled to the lift rod via a substantially horizontal arm extending from the rod. The substantially horizontal arm may be slotted. The lift rod may be coupled to a substantially vertical arm extending from the flapper cover top face, for instance via a slot on the lift rod and a pin on the vertical arm or vice versa. The vertical arm (and lift rod) may be located towards the center of the flapper cover top face. The flapper cover top face back may comprise an element adapted to couple with an arm extending from the front of the flapper, which arrangement may aid a peeling or an initial lift motion. The arm extending from the flapper cover front may be coupled to the element on the flapper cover back via a slot-and-pin attachment. 
     In some embodiments, the lift rod is coupled to the flapper cover towards the center of the cover. The lift rod may be associated with an element to guide its lifting and lowering motion. In some embodiments, the “guide element” may comprise a tubular body, within which the lift rod is disposed. The lift rod is in some embodiments substantially perpendicular with the flapper cover. In some embodiments, the guide element may comprise a tubular body having an essentially cylinder-like shape. In other embodiments, the guide element may also have a triangular, rectangular, square, oval, oblong, ovate, elliptic, obovate, cuneate, deltoid or orbicular shape. 
     In some embodiments, the assembly comprises an element configured to provide an “end point” or “stop” for the lifting flapper cover. In some embodiments, this “first stop element” is a ring or is ring-like. A first stop element may be supported by and coupled to the flush valve body, and may also be coupled to the guide element. A first stop element may be coupled to the flush valve body via one or more vertical arms. The vertical arms may be supported by a platform extending from the flush valve body, or from a platform about the valve inlet. In some embodiments, the first stop element is supported by and coupled to the flapper cover top face via one or more arms. The first stop element may be adapted to encourage the lifting flapper cover to be placed in a position where it is substantially parallel with the flush valve inlet and substantially perpendicular with the lift rod. In this embodiment, a full cylinder-shaped head space above the inlet may be provided. In some embodiments, the top face of the flapper cover may comprise an element configured to engage the first stop element as the flapper cover is lifted. This “second stop element” may be disposed towards the front of the flapper cover top face. The second stop element and/or the first stop element may comprise a feature to engage the other, for example a gear-like groove-and-ridge arrangement on one or the other or on both. A ridge is adapted to fit into and couple to a groove. 
     In some embodiments, the flapper cover is configured to partially lift or peel off from the front of the flapper cover towards the back. The flapper cover may be directly lowered to a closed position or further lifted to a fully open position. The flapper cover may be further lifted to an end-point or stopped position where it is substantially parallel with the flush valve inlet and perpendicular with the lift rod, thus providing a maximum fluid head space above the valve inlet. 
     In some embodiments, a multi-arm linkage may be configured to attach to both a front and a back of a flapper cover. In such embodiments, as a lift rod is actuated, it may partially lift or peel the flapper cover from both the front and back to partially open the flush valve. The flapper cover may be directly lowered to a closed position or further lifted to a fully open position. The flapper cover may be further lifted to an end-point or stopped position where it is substantially parallel with the flush valve inlet and perpendicular with the lift rod, thus providing a maximum fluid head space above the valve inlet. In such an embodiment, there may be two first and second stop elements. In other embodiments, a multi-arm linkage may be configured to attach to multiple points around a flapper cover top face, thereby adapted to partially lift or peel the flapper cover from around a partial or entire perimeter of the flapper cover. 
       FIG. 1A  depicts a perspective view of flush valve assembly  100  according to some embodiments. In this embodiment, planar flapper cover  101  is shown in a closed position over valve inlet  102 . Valve outlet  103  is ata bottom of valve body  104 . Flapper cover  101  contains flexible portion  105  and rigid portions  106 . Moveable rigid lift rod  107  is coupled to the flapper cover top face via multi-arm linkage  108 . Lift rod  107  is disposed within tubular guide element  109 . Visible towards the front of the flapper cover are pivot arm  110  and second stop element  111 . Second stop element  111  is adapted to engage ring-like first stop element  112  situated above valve inlet  102 . As the first and second stop elements engage and rod  107  continues to lift the flapper cover, the flapper cover is encouraged to enter into a position where it is substantially parallel with the valve inlet and substantially perpendicular with the lift rod. First stop element  112  is coupled to the valve body and guide element via vertical arms  113 . 
       FIG. 1B  is a side cut-away view of flush valve assembly  100  according to an embodiment that provides a more detailed view of multi-arm linkage  108 . Flapper cover  101  is in a closed position. Shown are curved pivot arm  110  containing joint  114  that allows pivot arm  110  to flex as it is moved by lift rod  107 . Pivot arm  110  is coupled to the front of flapper cover  101  top face and to horizontal arm  115  extending from lift rod  107 . Pivot arm  110  is connected to horizontal arm  115  and flapper cover  101  via joints  116  around which it can rotate. Lift rod  107  contains slot  120 , and is coupled to vertical arm  117  extending from the flapper cover top face via pin  121  on vertical arm  117 . First stop element  112  is supported by vertical arms  113  above valve inlet  102 . Second stop element  111  is coupled to the flapper cover top face front. When the lift rod lifts the flapper cover, the first and second stop elements engage, encouraging the flexible flapper cover to enter into a position wherein it is substantially parallel with the valve inlet and substantially perpendicular to the lift rod. The flapper cover top face back contains element  118  adapted to couple with arm  119  extending from the front of the flapper, which arrangement may aid a peeling or an initial lift motion. Arm  119  extending from the flapper cover front may be coupled to element  118  on the flapper cover back via a slot-and-pin attachment. 
       FIG. 2  shows flush valve assembly  200  according to an embodiment wherein the assembly is associated with hydraulic cylinder  250  for moving lift rod  207  to lift and lower flapper cover  201 . First stop element  212  contains feature  251  adapted to engage second stop element  211 . In this instance, feature  251  is a rounded element adapted to engage with curved second stop element  211 . In other embodiments, a lift rod may be powered with an electric motor, with a manual lever, or by a combination of these methods. Flapper cover  201  is shown partially raised above valve inlet  202 . 
       FIG. 3A ,  FIG. 3B  and  FIG. 3C  depict elliptical, non-circular flush valve body  304  in perspective, top and side views. Inlet portion  355  of flush valve body  304  is non-linearly downwardly-tapered from inlet  302  towards outlet  303 . Flush valve body  304  of  FIG. 3A ,  FIG. 3B  and  FIG. 3C  is generally symmetrical. 
       FIG. 4  shows a side cut-away view of flush valve assembly  400  according to an embodiment, wherein valve body  404  comprises lead-in lip  456  around an entirety of inlet  402 . Flush valve body  404  is non-linearly downwardly-tapered along portion  455  from inlet  402  to outlet  403 . Also visible is multi-arm linkage  408 , second stop element  411 , planar flapper cover  401  and lift rod  407 . In the embodiment of  FIG. 4 , lead-in lip  456  extends downward about 13% of the distance from the valve inlet  402  to valve outlet  403 . In other embodiments, a lead-in lip may extend downward from any of about 5%, about 7%, about 9%, about 11%, about 13%, about 15%, about 17% or about 19% to any of about 21%, about 23%, about 25%, about 27%, about 29%, about 31%, or more, of the distance from a valve inlet to a valve outlet. Flush valve body  404  is generally symmetrical. Visible are element  418  coupled to arm  419  extending from the front of flapper  401 , as well as pivot arm  410  and joint  414 . Lift rod  407  is coupled to vertical arm  417  via slot  420  and pin  421 , which arrangement allows for relative movement of  407 ,  417  and flapper cover  401 . Flapper cover  401  comprises rigid portions  406  and flexible portion  405 . 
       FIG. 5A  and  FIG. 5B  depict a side view and top view of flush valve body  504  according to an embodiment. Flush valve body  504  comprises lead-in lip  556  extending around an entirety of inlet  502 . Inlet  502  is a highest point of valve body  504 . Valve body  504  extends from inlet  502  to outlet  503 . Valve body  504  is non-linearly downwardly-tapered and is also non-symmetrical. Valve body front  560  is more tapered than valve body back  561  and the front therefore provides a longer liquid flow path.  FIG. 5A  and  FIG. 5B  show valve outlet center  562  is not aligned with valve inlet center  563  along an x-z plane or along an x-y plane. Valve body  504  comprises a substantially symmetrical, cylindrical outlet portion  564  and a non-symmetrical downwardly-tapered inlet portion  555 . 
       FIG. 6A  and  FIG. 6B  depict in-wall toilet tank assembly  680  according to an embodiment.  FIG. 6A  is a front, top, perspective view and  FIG. 6B  is a front view. Assembly  680  comprises rectangular box-shaped tank  690 . Elliptical jet flush valve assembly  600 J is positioned lower than elliptical rim flush valve assembly  600 R. In this embodiment, jet flush valve inlet  602 J sits about  8  inches lower than rim flush valve inlet  602 R. Both jet flush valve assembly  600 J and rim flush valve assembly  600 R comprise a moveable rigid lift rod disposed in tubular guide elements  609 J and  609 R. Lift rod  607 J is coupled to jet flush valve planar flapper  601 J via multi-arm linkage  608 J while the lift rod  607 R is coupled to rim flush valve planar flapper  601 R via multi-arm linkage  608 R. Tank  690  comprises window  691  to allow for installation of flush actuation assembly  692 . Actuation assembly  692  is coupled to rigid lift rods coupled to rim flush valve flapper cover  601 R and jet flush valve flapper cover  601 J. Actuation assembly  692  may be configured to open rim and jet flush valves simultaneously or independently. Actuation assembly  692  may be associated with one or more manual buttons or levers, or may be associated with an electric motor, a piston, a hydraulic cylinder, a pneumatic cylinder, etc. Fluid from the tank will exit rim and flush valve bodies  604 R and  604 J through rim conduit  694 R and jet conduit  694 J, respectively. In this embodiment, overflow tube  693  is coupled to and in fluid communication with conduit  694 R inside tank  690 . Rim conduit outlet  695 R and jet conduit outlet  695 J will be in fluid communication with a rim inlet port and a jet inlet port, respectively. Conduits  694 R and  694 J make substantially right angle bends from a downward flow path from flush valve outlets towards outlets  695 R and  695 J. Water level W, when a tank contains water prior to a flush cycle, is about 16 inches from the tank interior floor, at which level a water volume is roughly 3 gallons. Tank  680  is configured to deliver about 4.8 liters per flush cycle (lpf), or about 1.3 gallons per flush cycle. Also in this embodiment, tank  690  dimensions are about 24.2 inches in height, about 14.5 inches in width, and about 3.4 inches in depth (front to back), based on the tank exterior. The tank walls are about 0.25 inches thick. In this embodiment, rim flush valve body  604 R is about 80% of the size of jet flush valve body  604 J, as measured by any dimension, for instance by inlet area. 
       FIG. 6C ,  FIG. 6D ,  FIG. 6E , and  FIG. 6F  show left side, right side, back, and front views of flush valve assembly  600 , respectively, according to an embodiment. Flush valve assembly  600  may represent either jet flush valve assembly  600 J or rim flush valve assembly  600 R. Flapper cover  601  is in a closed position enclosing flush valve inlet  602 . Valve body  604  extends from inlet  602  to outlet  603 . Planar flapper cover  601  contains flexible portion  605  and rigid portions  606 . Flapper cover  601 , inlet  602 , and outlet  603  comprise an elliptical shape. Flush valve assembly  600  comprises multi-arm linkage  608  coupled to flapper cover  601  top face and lift rod  607 . Valve body  604  comprises lead-in lip  656  extending partially around a perimeter of flush valve body  604 . Multi-arm linkage  608  contains second stop element  611 . Assembly  600  contains elliptical, ring-shaped first stop element  612  containing rod-shaped configured to engage upwardly-curved second stop element  611 . Lift rod  607  is disposed in guide element  609 . Multi-arm linkage  608  comprises complimentary features on either side of lift arm  607 . Visible are pivot arm  610  and joint  614 . 
       FIG. 6G ,  FIG. 6H , and  FIG. 6I  show cross-section, left side views of flush valve assembly  600  in various stages of flapper cover  601  being lifted, according to some embodiments. In  FIG. 6G , flapper cover  601  is partially lifted in a peeling motion from front to back, partially opening the flush valve. As flapper cover  601  is lifted, arm  619  is able to rotatably move relative to feature  618  via a slot-and-pin coupling. Features  618  and  619  are present on left and right sides of flapper cover  601 . Flexible portion  605  allows for a peeling motion.  FIG. 6H  shows second stop element  611  engaging feature  612  as lift rod  607  is further lifted. As second stop element  611  engages feature  612 , multi-arm linkage  608  is encouraged to lift flapper cover  601  from the back face. Flush valve cover  601  may be lowered to enclose inlet  602  to close the flush valve from a partially opened position to provide a partial low volume flush. Alternatively, lift rod  607  may continue to lift flapper cover  601  to provide a substantially symmetrical, substantially cylinder-shaped full head space  699  above inlet  602  as depicted in  FIG. 6I . A full head space above valve inlet  602  may provide for a full flush. Flapper cover  601  is substantially parallel with valve inlet  602  and substantially perpendicular to lift rod  607  in  FIG. 6I . Visible are slot  620  and pin  621 . 
       FIG. 7  shows a portion  780  of an in-wall toilet tank assembly, according to an embodiment. Tank  790  comprises window  791  for installation of an actuation assembly. Jet conduit  794 J is adjacent rim conduit  794 R. In this embodiment, overflow tube  793  is connected to rim conduit  794 R at an exterior of tank  790 . 
       FIG. 8A  and  FIG. 8B  depict bowl  800 , according to some embodiments. Upon initiation of a flush cycle, water will be discharged from a tank along jet flow path J and rim flow path R. Water discharged from a rim flush valve will enter rim manifold  801 R, enter rim inlet port  802 R, and exit rim outlet port  803 R to rim  804  where it washes down and cleanses bowl interior surface  805 . Water discharged from a jet flush valve will enter jet manifold  801 J, enter jet inlet port  802 J, and exit jet outlet port  803 J, where it will pass through jet trap  806  and into trapway inlet  807  and initiate a siphon. 
     In some embodiments, suitable flush valve assemblies may be found in U.S. app. Nos. PCT/US2019/038648, filed Jun. 24, 2019, and U.S. app. No. PCT/US2019/062912, filed Nov. 25, 2019. 
     In some embodiments, the toilet system may comprise both a jet flush valve assembly and a rim flush valve assembly. In some embodiments, a rim flush valve assembly will be associated with an overflow tube. In some embodiments, a rim flush valve inlet may be positioned at a higher point in the tank than a jet flush valve inlet. A higher point meaning for example higher from a toilet tank bottom (floor). In such embodiments, a rim flush valve body may be longer than a jet flush valve body. In other embodiments, a rim flush valve body may have a same length as a jet flush valve body, and wherein a rim conduit extends longer into the tank, thus raising the rim flush valve inlet to a higher point. 
     In some embodiments, a rim flush valve inlet may be positioned above a jet flush valve inlet in a tank assembly. In certain embodiments, a rim flush valve inlet may be positioned from any of about 4.0 inches, about 4.5 inches, about 5.0 inches, about 5.5 inches, or about 6.0 inches, to any of about 6.5 inches, about 7.0 inches, about 7.5 inches, about 8.0 inches, about 8.5 inches, about 9.0 inches, about 9.5 inches, about 10.0 inches, about 10.5 inches, about 11.0 inches, or more, above a jet flush valve inlet (difference in inlet heights). 
     In some embodiments, a rim flush valve body may be smaller than a jet flush valve body, for example smaller in a length from inlet to outlet and/or in inlet area and/or outlet area. For example, a rim flush valve body may be from any of about 60%, about 65%, about 70%, or about 75%, to any of about 80%, about 85%, about 90%, or about 95%, of the size of a jet flush valve body size. In some embodiments, a rim flush valve body may be about the same size of a jet flush valve body. 
     A relative size of a rim flush valve body and a jet flush valve body may be employed to help determine a desired flow rate and volume through each valve required to cleanse the bowl and initiate a siphon, respectively. 
     A rim valve inlet set height may be configured to adjust an amount of tank flush water above a rim valve inlet prior to initiation of a flush cycle, and thereby how much tank water is discharged through a rim valve during a flush cycle. A rim valve inlet set height may be positioned relative to a jet valve inlet height to provide a simple system to adjust relative water discharge volumes between a rim flush valve and a jet flush valve. A volume of tank water below the rim valve inlet will be concentrated towards the jet valve during a flush cycle and may improve a jet flow rate. A difference in height between a rim flush valve and a jet flush valve may also alleviate space constraints and may allow for larger valves to be positioned within a tank. 
     In some embodiments, flush water delivery to a jet outlet may be independent from flush water delivery to a rim outlet, that is, a rim pathway and a jet pathway may be isolated and independent, from a rim flush valve outlet to a rim outlet port and from a jet flush valve outlet to a jet outlet port, respectively. Water delivered to a rim is delivered to a bowl upper perimeter which serves to wash-down and cleanse the bowl. In some embodiments, flush water delivered through a jet valve and through a rim valve may merge only in a bowl sump area. 
     In general, a ratio of a volume of fluid delivered to the rim to a volume of fluid delivered to the jet may also affect toilet performance. In typical siphonic jetted toilets, about 70% or more of the flush water is required to power the jet and initiate the siphon, leaving only about 30% or less to cleanse the bowl through the rim. In some embodiments of a present system, less water is required to initiate a siphon, which allows more water to be used in cleaning the bowl via the rim. In some embodiments of the present system, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, or about 70%, or more of the flush water can be directed to the rim for significant improvement in bowl cleaning. 
     In some embodiments, upon initiation of a flush cycle, opening of the rim flush valve is started prior to opening the jet flush valve; that is, lifting of the rim flush valve flapper cover is initiated prior to lifting of the jet flush valve flapper cover. In some embodiments, both the rim flush valve and the jet flush valve are in a fully open position (full head space) simultaneously, and the jet flush valve is closed prior to closing the rim flush valve. 
     In some embodiments, lifting of a rim flush valve flapper cover may be initiated immediately upon the start of a flush cycle. In some embodiments, lifting of a rim flush valve flapper cover may be initiated from any of about 0.1 seconds, about 0.2 seconds, about 0.3 seconds, about 0.4 second, about 0.5 seconds, or about 0.6 seconds, to any of about 0.7 seconds, about 0.8 seconds, about 0.9 seconds, about 1.0 seconds, about 1.1 seconds, about 1.2 seconds, or more after the start of a flush cycle. In some embodiments, a rim flush valve may be returned to a fully closed position from any of about 0.3 seconds, about 0.6 seconds, about 0.9 seconds, about 1.2 second, about 1.5 seconds, or about 1.8 seconds, to any of about 2.1 seconds, about 2.4 seconds, about 2.7 seconds, about 3.0 seconds, about 3.3 seconds, about 3.6 seconds, or more after the start of a flush cycle. 
     In some embodiments, lifting of a jet flush valve flapper cover may be initiated from any of about 0.1 seconds, about 0.2 seconds, about 0.4 seconds, about 0.6 second, about 0.8 seconds, or about 1.0 seconds, to any of about 1.2 seconds, about 1.4 seconds, about 1.6 seconds, about 1.8 seconds, about 2.0 seconds, about 2.2 seconds, or more after the start of a flush cycle. In some embodiments, a jet flush valve may be returned to a fully closed position from any of about 0.3 seconds, about 0.5 seconds, about 0.7 seconds, about 0.9 second, about 1.1 seconds, or about 1.3 seconds, to any of about 1.5 seconds, about 1.7 seconds, about 1.9 seconds, about 2.1 seconds, about 2.3 seconds, about 2.6 seconds, or more after the start of a flush cycle. 
     Initiation or “start of a flush cycle” may mean the moment an operator begins a flush by turning a handle or lever, pushing a button, activating a sensor, etc. 
     In some embodiments, a total amount of flush water delivered during a flush cycle is 5.5 liters or less, about 5.2 liters or less, about 4.8 liters or less, about 4.6 liters or less, about 4.4 liters or less, about 4.2 liters or less, about 4.0 liters or less, about 3.8 liters or less, about 3.6 liters or less, about 3.4 liters or less, about 3.2 liters or less, about 3.0 liters or less, about 2.8 liters or less, about 2.6 liters or less, about 2.4 liters or less, about 2.2 liters or less, or about 2.0 liters or less. 
     In some embodiments, a total amount of flush water delivered through a rim flush valve during a flush cycle may be from any of about 1.0 liters, about 1.5 liters, about 2.0 liters, or about 2.5 liters, to any of about 3.0 liters, about 3.5 liters, about 4.0 liters, about 4.5 liters, or more. 
     In some embodiments, a total amount of flush water delivered through a jet flush valve during a flush cycle may be from any of about 1.0 liters, about 1.5 liters, about 2.0 liters, or about 2.5 liters, to any of about 3.0 liters, about 3.5 liters, about 4.0 liters, about 4.5 liters, or more. 
     In some embodiments, the system may comprise a jet conduit, which jet conduit is in fluid communication with a jet flush valve outlet and a jet inlet port. In some embodiments, the system may comprise a rim conduit, which rim conduit is in fluid communication with a rim flush valve outlet and a rim inlet port. A conduit is configured to receive fluid from a flush valve outlet and to deliver fluid to a rim inlet port and/or a jet inlet port. 
     In some embodiments, the toilet bowl assembly comprises jet fluid pathway that includes a jet channel disposed within the bowl wall. The jet channel may have various configurations and extension areas, additional ports or side-channels, and the like depending on the bowl mold geometry, including an optional jet manifold so long as the jet fluid pathway receives fluid from the jet valve outlet into a jet inlet port and into and through a jet channel to a jet outlet port. A jet manifold is in fluid communication with a jet flush valve outlet and a jet inlet port. In some embodiments, a jet fluid pathway is configured to remain in a primed state, and substantially isolates it thereby assisting in preventing air from entering into the jet channel. This is accomplished by (1) isolating the jet channel from rim flow or other pathways open to the atmosphere, (2) closing the jet channel flush valve before the level of water in the tank falls to the level of the opening of the flush valve, (3) helping to prevent air flow from entering the jet channel and any other jet paths, areas, or an optional jet manifold if used, which in one embodiment may include establishing a seal depth in a jet trap in the sump area to assist in blocking air from entering the jet channel outlet and/or (4) configuring and operating the assembly to ensure that the water level in the jet trap does not fall to a level that enables air to travel back up and into the jet channel. 
     In some embodiments, a jet fluid pathway may comprise a jet channel and a jet manifold. In some embodiments, once primed with water, a jet channel may remain primed before actuation of and after completion of a flush cycle. In some embodiments, once primed with water, a jet channel and a jet manifold may remain primed before actuation of and after completion of a flush cycle. In some embodiments, a jet fluid pathway may comprise a jet channel and a jet conduit. In some embodiments, once primed with water, a jet channel and a jet conduit may remain primed before actuation of and after completion of a flush cycle. In some embodiments, a jet channel, a jet manifold, and a jet conduit may remain primed before actuation of and after completion of a flush cycle. 
     Sufficient post-flush depth in the sump area and/or stopping water from entering the jet fluid pathway through the jet outlet port can also be achieved by maintaining flow of water to a rim shelf or through a rim channel while the siphon is breaking. As the toilet system in some embodiments herein includes separate channels and valve mechanisms for controlling flow to the rim and jet, the system can be designed to continue flow through the rim inlet port during the siphon break. The flow of water to the rim inlet port may be designed to be sufficient to maintain the level of water in the sump area above the height of the jet outlet port, yet insufficient to maintain the siphon in the trapway. In this manner, added security can be provided for maintaining the jet channel free of air, reducing the dependence on a seal depth in the sump area. It should be noted that the flow through the jet and rim can also be utilized together to maintain sufficient post-flush depth in the sump area. 
     Also disclosed is a flush toilet system comprising a bowl, a tank, a rim flush valve assembly and/or a jet flush valve assembly, an overflow tube, and a rim conduit and/or a jet conduit, wherein the flush valve assembly is positioned in an interior space of the tank; the flush valve assembly comprises a flush valve body extending from a flush valve inlet to a flush valve outlet; the conduit is in fluid communication with the flush valve outlet and rim inlet port or a jet inlet port; and wherein the overflow tube is coupled to and in fluid communication with a conduit. 
     In some embodiments, the overflow tube is coupled to a conduit outside of the tank, thus providing more space in a toilet tank interior. The overflow tube may be substantially L-shaped, having an elbow. In some embodiments an overflow tube is configured to hold a cleaning tablet. For instance, a cleaning tablet may be dropped into a top of the overflow tube where it may rest in or near an elbow. As a bowl is filled with fresh water from water entering the overflow tube from a fill valve, cleaning agent will be carried with the water and passed to the bowl. The term “coupled outside of the tank” means the connection point is outside the tank (at an exterior of the tank). 
     In some embodiments, the flush toilet system having an overflow tube coupled to a conduit comprises a rim flush valve assembly coupled to a rim conduit; a jet flush valve assembly coupled to a jet conduit; and an overflow tube coupled to and in fluid communication with the rim conduit. In some embodiments, an overflow tube is coupled to and in fluid communication with a rim conduit outside of the tank. In addition to providing more space in the tank, this may allow for better functioning of the rim flush. 
     In some embodiments, a rim flush valve or jet flush valve outlet may have a cross-sectional surface area of from any of about 8 cm 2 , about 9 cm 2 , 10 cm 2 , about 12 cm 2 , about 14 cm 2 , about 16 cm 2  or about 18 cm 2  to any of about 20 cm 2 , about 22 cm 2 , about 24 cm 2 , about 26 cm 2 , about 28 cm 2 , about 30 cm 2  or about 32 cm 2 . Likewise, a rim or jet conduit may have a same or similar internal cross-sectional area. In some embodiments, an overflow pipe may have an internal cross-sectional area of from any of about 3.5 cm 2 , about 3.8 cm 2 , about 4.1 cm 2 , about 4.4 cm 2 , about 4.7 cm 2 , about 5.0 cm 2  or about 5.3 cm 2 , to any of about 5.6 cm 2 , about 5.9 cm 2 , about 6.2 cm 2 , about 6.5 cm 2 , about 6.8 cm 2 , about 7.1 cm 2 , about 7.4 cm 2 , about 7.7 cm 2 , about 8.0 cm 2 , about 8.3 cm 2 , about 8.5 cm 2 , about 8.8 cm 2 , about 9.1 cm 2  or about 9.4 cm 2 , or higher. 
     Following are some non-limiting embodiments of the disclosure. 
     In a first embodiment, disclosed is a siphonic flush toilet system, the system comprising a bowl, a tank, and a rim flush valve assembly and/or a jet flush valve assembly, wherein the bowl comprises a rim extending at least partially around a bowl upper perimeter; an interior surface and an exterior surface; a wall defining the interior surface and exterior surface; and a sump area; the tank comprises an interior space configured to hold fluid; and a height, a width, and a depth, based on a tank exterior, wherein the height is from about 17.0 inches to about 29.0 inches; the width is from about 10.5 inches to about 18.5 inches; and he depth is from about 3.10 inches to about 3.60 inches; and the flush valve assembly comprises a flush valve body extending from a flush valve inlet to a flush valve outlet; a flapper cover having a top face and a bottom face and a front and a back; and a flush actuator comprising a lift rod; wherein the sump area is configured to be in fluid communication a trapway inlet; the flush valve assembly is positioned in the interior space of the tank; the bottom face of the flapper cover is configured to enclose the flush valve inlet; and the lift rod is coupled to the top face of the flapper cover and is configured to lift the flapper cover to open the flush valve. 
     In a second embodiment, disclosed is a flush toilet system according to embodiment 1 comprising a trapway, wherein the trapway comprises a weir, a trapway inlet, and a trapway outlet, and wherein the trapway is in fluid communication with the bowl sump area. 
     In a third embodiment, disclosed is a flush toilet system according to embodiments 1 or 2, comprising a rim flush valve assembly comprising a rim flush valve body extending from a rim flush valve inlet to a rim flush valve outlet; a jet flush valve assembly comprising a jet flush valve body extending from a jet flush valve inlet to a jet flush valve outlet; a jet fluid pathway extending from the jet flush valve outlet to a jet outlet port; a jet channel disposed within the bowl wall and extending from a jet inlet port to the jet outlet port; and a rim channel disposed within the rim and extending from a rim inlet port to a rim outlet port; wherein the rim inlet port is in fluid communication with the rim flush valve outlet and the rim outlet port is in fluid communication with the bowl interior surface; and the jet inlet port is in fluid communication with the jet flush valve outlet and the jet outlet port is configured to discharge fluid to the bowl sump area. 
     In a fourth embodiment, disclosed is a flush toilet system according to any of the preceding embodiments, comprising a jet flush valve assembly and a jet fluid pathway extending from a jet flush valve outlet to a jet outlet port, and wherein, once primed, the jet fluid pathway is capable of remaining primed with fluid before actuation of and after completion of a flush cycle. 
     In a fifth embodiment, disclosed is a flush toilet system according to any of the preceding embodiments, wherein the bowl sump area comprises a jet trap defined by the interior surface of the bowl, the jet trap having an jet trap inlet end and a jet trap outlet end, wherein the jet trap inlet end is configured to receive fluid from the jet outlet port and/or the interior surface of the bowl and the jet trap outlet end is configured to be in fluid communication with the trapway inlet, and wherein the jet trap comprises a seal depth. 
     In a sixth embodiment, disclosed is a flush toilet system according to embodiment 5, wherein an upper surface of the jet outlet port is within the jet trap and is positioned at a seal depth below an upper surface of the trapway inlet as measured longitudinally through the sump area. 
     In a seventh embodiment, disclosed is a flush toilet system according to any of the preceding embodiments, wherein the lift rod is configured to lift the flapper cover to partially open the flush valve; to fully open the flush valve and to dispose the flapper cover in a position wherein the bottom face is substantially parallel with the flush valve inlet when the flush valve is fully open. 
     In an eighth embodiment, disclosed is a flush toilet system according to any of the preceding embodiments, wherein the flapper cover is configured to lift in a peeling motion from the flapper cover front towards the flapper cover back. In a ninth embodiment, disclosed is a flush toilet system according to any of the preceding embodiments, wherein the flapper cover comprises a flexible portion. In a tenth embodiment, disclosed is a flush toilet system according to any of the preceding embodiments, wherein the flapper cover comprises a flexible portion and a rigid portion. 
     In an eleventh embodiment, disclosed is a flush toilet system according to any of the preceding embodiments, wherein the bottom face of the flapper cover comprises a continuous flexible portion. In a twelfth embodiment, disclosed is a flush toilet system according to any of the preceding embodiments, wherein the top face of the flapper cover comprises one or more flexible portions and one or more rigid portions. 
     In a thirteenth embodiment, disclosed is a flush toilet system according to any of the preceding embodiments, wherein the lift rod is coupled to the top face of the flapper cover via a multi-arm linkage. In a fourteenth embodiment, disclosed is a flush toilet system according to any of the preceding embodiments, wherein the lift rod is coupled to the top face of the flapper cover via a multi-arm linkage comprising a pivot arm. In a fifteenth embodiment, disclosed is a flush toilet system according to any of the preceding embodiments, wherein the lift rod is coupled to the top face of the flapper cover via a multi-arm linkage comprising one or more slotted elements. 
     In a sixteenth embodiment, disclosed is a flush toilet system according to any of the preceding embodiments, wherein the lift rod is coupled to the top face of the flapper cover via a multi-arm linkage comprising one or more slot-and-pin elements. In a seventeenth embodiment disclosed is a flush toilet system according to any of the preceding embodiments, wherein the lift rod is substantially perpendicular to the flapper cover face. In an eighteenth embodiment, disclosed is a flush toilet system according to any of the preceding embodiments, wherein the lift rod is disposed in a tubular body guide element, wherein the tubular body guide element is coupled to the flush valve body. 
     In a nineteenth embodiment, disclosed is a flush toilet system according to any of the preceding embodiments, wherein the flush valve assembly comprises a stop element configured to provide a lift end-point of the flapper cover. In a twentieth embodiment, disclosed is a flush toilet system according to any of the preceding embodiments, wherein the flush valve assembly comprises a stop element configured to provide a lift end-point of the flapper cover, wherein the stop element is from about 2.5 cm to about 5.2 cm above the flush valve inlet. 
     In a twenty-first embodiment, disclosed is a flush toilet system according to any of the preceding embodiments, wherein the flush valve assembly comprises a first stop element above the flush valve inlet and second stop element disposed on the flapper cover top face, wherein the first stop element is configured to engage the second stop element. 
     In a twenty-second embodiment, disclosed is a flush toilet system according to any of the preceding embodiments, wherein the flush valve body inlet is triangular, rectangular, square, oval, oblong, ovate, elliptic, obovate, cuneate, deltoid or orbicular. In a twenty-third embodiment, disclosed is a flush toilet system according to any of the preceding embodiments, wherein the flush valve body comprises a lead-in lip. 
     In a twenty-fourth embodiment, disclosed is a flush toilet system according to any of the preceding embodiments, wherein the flush valve assembly does not include a back-flow preventer mechanism. 
     In a twenty-fifth embodiment, disclosed is a flush toilet system according to any of the preceding embodiments, wherein the flush valve inlet is radiused. In a twenty-sixth embodiment, disclosed is a flush toilet system according to any of the preceding embodiments, wherein the flush valve body is downwardly-tapered. In a twenty-seventh embodiment, disclosed is a flush toilet system according to any of the preceding embodiments, wherein the flush valve body is non-symmetrical. 
     In a twenty-eighth embodiment, disclosed is a flush toilet system according to any of the preceding embodiments, wherein the flush actuator is associated with an electric motor, a hydraulic cylinder, a pneumatic cylinder, a piston, a manual lever, a push button, or a combination thereof. 
     In a twenty-ninth embodiment, disclosed is a flush toilet system according to any of the preceding embodiments, wherein the toilet is a non-jetted, rim jetted, or direct jetted gravity powered siphonic toilet. 
     In a thirtieth embodiment, disclosed is a flush toilet system according to any of the preceding embodiments, wherein the trapway inlet is configured to be in a bathroom. In a thirty-first embodiment, disclosed is a flush toilet system according to any of the preceding embodiments, wherein two separate portions of the trapway are configured to be installed in a bathroom wall cavity. In a thirty-second embodiment, disclosed is a flush toilet system according to any of the preceding embodiments, wherein the trapway outlet is configured to be within a bathroom wall cavity. In a thirty-third embodiment, disclosed is a flush toilet system according to any of the preceding embodiments, wherein the toilet tank is configured to be installed in a bathroom wall cavity. 
     Another set of embodiments of the disclosure include the following. 
     In a first embodiment, disclosed is a flush toilet system comprising a bowl, a tank, a rim flush valve assembly and/or a jet flush valve assembly, an overflow tube, and a rim conduit and/or a jet conduit, wherein the flush valve assembly is positioned in an interior space of the tank; the flush valve assembly comprises a flush valve body extending from a flush valve inlet to a flush valve outlet; the conduit is in fluid communication with the flush valve outlet and a rim inlet port or a jet inlet port; and wherein the overflow tube is coupled to and in fluid communication with the conduit. 
     In a second embodiment, disclosed is a flush toilet system according to embodiment 1, wherein the overflow tube is coupled to the conduit outside of the tank. In a third embodiment, disclosed is a flush toilet system according to embodiments 1 or 2, wherein the overflow tube is configured to hold a cleaning tablet. 
     In a fourth embodiment, disclosed is a flush toilet system according to any of the preceding embodiments, comprising a rim flush valve assembly coupled to a rim conduit; a jet flush valve assembly coupled to a jet conduit; and an overflow tube coupled to and in fluid communication with the rim conduit. 
     In a fifth embodiment, disclosed is a flush toilet system according to any of the preceding embodiments, comprising a jet flush valve assembly and a jet fluid pathway extending from a jet flush valve outlet to a jet outlet port, and wherein, once primed, the jet fluid pathway is capable of remaining primed with fluid before actuation of and after completion of a flush cycle. 
     In a sixth embodiment, disclosed is a flush toilet system according to any of the preceding embodiments, wherein the bowl sump area comprises a jet trap defined by the interior surface of the bowl, the jet trap having an jet trap inlet end and a jet trap outlet end, wherein the jet trap inlet end is configured to receive fluid from the jet outlet port and/or the interior surface of the bowl and the jet trap outlet end is configured to be in fluid communication with the trapway inlet, and wherein the jet trap comprises a seal depth. 
     In a seventh embodiment, disclosed is a flush toilet system according to any of the preceding embodiments, wherein the flush valve assembly comprises a flapper cover having a top face and a bottom face and a front and a back; and a flush actuator comprising a lift rod; wherein the bottom face of the flapper cover is configured to enclose the flush valve inlet; and the lift rod is coupled to the top face of the flapper cover and is configured to lift the flapper cover to open the flush valve. 
     In an eighth embodiment, disclosed is a flush toilet system according to embodiment 7, wherein the lift rod is configured to lift the flapper cover to partially open the flush valve; to fully open the flush valve and to dispose the flapper cover in a position wherein the bottom face is substantially parallel with the flush valve inlet when the flush valve is fully open. In a ninth embodiment, disclosed is a flush toilet system according to embodiments 7 or 8, wherein the flapper cover is configured to lift in a peeling motion from the flapper cover front towards the flapper cover back. 
     In a tenth embodiment, disclosed is a flush toilet system according to any of embodiments 7 to 9, wherein the lift rod is configured to lift the flapper cover to partially open the flush valve; to fully open the flush valve and to dispose the flapper cover in a position wherein the bottom face is substantially parallel with the flush valve inlet when the flush valve is fully open. 
     A further set of embodiments include the following. 
     In a first embodiment, disclosed is a toilet tank assembly for a siphonic flush toilet system, the tank comprising an interior space configured to hold fluid; and a height, a width, and a depth, based on a tank exterior, wherein the height is from about 17.0 inches to about 29.0 inches; the width is from about 10.5 inches to about 18.5 inches; and he depth is from about 3.10 inches to about 3.60 inches. 
     In a second embodiment, disclosed is a toilet tank assembly according to embodiment 1, comprising a flush valve assembly positioned in the interior space of the tank, the flush valve assembly comprising a flush valve body extending from a flush valve inlet to a flush valve outlet; a flapper cover having a top face and a bottom face and a front and a back; and a flush actuator comprising a lift rod. 
     In a third embodiment, disclosed is a toilet tank assembly according to embodiments 1 or 2, comprising a rim flush valve assembly and/or a jet flush valve assembly, an overflow tube, and a rim conduit and/or a jet conduit, wherein the flush valve assembly is positioned in the interior space of the tank; the overflow is positioned at least partially in the interior space of the tank; the flush valve assembly comprises a flush valve body extending from a flush valve inlet to a flush valve outlet; the conduit is in fluid communication with the flush valve outlet and a rim inlet port or a jet inlet port; and wherein the overflow tube is coupled to and in fluid communication with the conduit. 
     In a fourth embodiment, disclosed is a toilet tank assembly according to embodiment 3, wherein the overflow tube is positioned both in the interior space of the tank and exterior to the tank, and wherein the overflow tube is coupled to the conduit outside of the tank. In a fifth embodiment, disclosed is a toilet tank assembly according to embodiments 3 or 4, wherein the overflow tube is configured to hold a cleaning tablet. 
     In a sixth embodiment, disclosed is a toilet tank assembly according to any of embodiments 2 to 5, comprising a rim flush valve assembly coupled to a rim conduit; a jet flush valve assembly coupled to a jet conduit; and an overflow tube coupled to and in fluid communication with the rim conduit. 
     In a seventh embodiment, disclosed is a toilet tank assembly according to any of embodiments 2 to 6, comprising a jet flush valve assembly configured to be in fluid communication with a jet fluid pathway extending from a jet flush valve outlet to a jet outlet port, and wherein, once primed, the jet fluid pathway is capable of remaining primed with fluid before actuation of and after completion of a flush cycle. 
     In an eighth embodiment, disclosed is a toilet tank assembly according to any of embodiments 2 to 7, wherein the bottom face of the flapper cover is configured to enclose the flush valve inlet; and the lift rod is coupled to the top face of the flapper cover and is configured to lift the flapper cover to open the flush valve. In a ninth embodiment, disclosed is a toilet tank assembly according to any of embodiments 2 to 8, wherein the lift rod is configured to lift the flapper cover to partially open the flush valve; to fully open the flush valve and to dispose the flapper cover in a position wherein the bottom face is substantially parallel with the flush valve inlet when the flush valve is fully open. 
     In a tenth embodiment, disclosed is a toilet tank assembly according to any of embodiments 2 to 9, wherein the flapper cover is configured to lift in a peeling motion from the flapper cover front towards the flapper cover back. In an eleventh embodiment, disclosed is a toilet tank assembly according to any of embodiments 2 to 10, wherein the lift rod is configured to lift the flapper cover to partially open the flush valve; to fully open the flush valve and to dispose the flapper cover in a position wherein the bottom face is substantially parallel with the flush valve inlet when the flush valve is fully open. 
     In a twelfth embodiment, disclosed is a toilet tank assembly according to any of the preceding embodiments, wherein the toilet tank is configured to be installed in a bathroom wall cavity. 
     The term “coupled” means that an element is “attached to” or “associated with” another element. Coupled may mean directly coupled or coupled through or via one or more other elements. An element may be coupled to an element through two or more other elements in a sequential manner or a non-sequential manner. The term “via” in reference to “via an element” may mean “through” or “by” an element. Coupled or “associated with” may also mean elements not directly or indirectly attached, but that they “go together” in that one may function together with the other. 
     The term “fluid communication” means for example configured for liquid or gas flow there through and may be synonymous with “fluidly coupled” or “flow communication”. 
     The term “towards” in reference to a of point of attachment, may mean at exactly that location or point or, alternatively, may mean closer to that point than to another distinct point, for example “towards a center” means closer to a center than to an edge. 
     The term “like” means similar and not necessarily exactly like. For instance “ring-like” means generally shaped like a ring, but not necessarily perfectly circular. 
     The articles “a” and “an” herein refer to one or to more than one (e.g. at least one) of the grammatical object. Any ranges cited herein are inclusive. The term “about” used throughout is used to describe and account for small fluctuations. For instance, “about” may mean the numeric value may be modified by ±0.05%, ±0.1%, ±0.2%, ±0.3%, ±0.4%, ±0.5%, ±1%, ±2%, ±3%, ±4%, ±5%, ±6%, ±7%, ±8%, ±9%, ±10% or more. All numeric values are modified by the term “about” whether or not explicitly indicated. Numeric values modified by the term “about” include the specific identified value. For example “about 5.0” includes 5.0. 
     The term “substantially” is similar to “about” in that the defined term may vary from for example by ±0.05%, ±0.1%, ±0.2%, ±0.3%, ±0.4%, ±0.5%, ±1%, ±2%, ±3%, ±4%, ±5%, ±6%, ±7%, ±8%, ±9%, ±10% or more of the definition; for example the term “substantially perpendicular” may mean the 90° perpendicular angle may mean “about 90°”. The term “generally” may be equivalent to “substantially”. 
     Features described in connection with one embodiment of the disclosure may be used in conjunction with other embodiments, even if not explicitly stated. 
     Embodiments of the disclosure include any and all parts and/or portions of the embodiments, claims, description and figures. Embodiments of the disclosure also include any and all combinations and/or sub-combinations of embodiments. 
     All U.S. patent applications, published patent applications and patents referred to herein are hereby incorporated by reference.