You are an expert at summarizing long articles. Proceed to summarize the following text:

You are an expert at summarizing long articles. Proceed to summarize the following text: 
This application claims priority from provisional application 60/460,550 filed Apr. 4, 2003. 

   FIELD OF THE INVENTION 
   The invention relates to a toilet flush system, more particularly a pressurized dual flush system. 
   BACKGROUND OF THE INVENTION 
   A conventional pressure flush system uses a pressure water vessel disposed inside a toilet water tank. When water is infused into the vessel, the air in the water vessel is compressed and pressure accumulates inside the vessel. When a flush is needed, a user discharges the pressurized water through a discharge valve and through a toilet bowl trapway in order to provide a flushing action. 
   Thus, a pressure flush system utilizes compressed air to drive water into the bowl instead of the “pulling” or siphon action of gravity style toilets. As the result, a little amount of water provides a full and effective flushing of the pressure flush toilet. 
   The typical structure of a prior art pressure flush system is described in patent to Martin, 1977 (No.4233698), which primarily includes the pressure water vessel, flush valve, control valve refill valve, and air induction valve used to add pressure to the flush valve. In such a system, however, there are some problems as follows:
         1. The flush valve of the system has only one single flush function. That is to say that once the control valve opens the flush valve, all volume of water in the water vessel will be flush out. Under this method the adjustment of discharge volume is not allowed.   2. There is only one secure device taken in the air induction valve. Since the water vessel is sealed, pressure must be contained. Any excess pressure over the strictly preset limitation may be dangerous. Therefore, there is potential safety concern if there was only one discharge protector used.   3. The refill rate is not adjustable. The refill volume may be too much or too little when the system is used with differently designed toilet bowls.   4. The flush valve cannot be shut off when a low pressure occurs in the water supply pipe, and this may cause water leaking from the pressure vessel.       

   Another prior art example is the reissued patent Martin et al., 2002 (NO.RE37921E7), which comprises a water vessel, an external manifold mounted directly on said vessel, and an internally mounted flush valve assembly. The manifold comprises a water pressure regulator, an air induction system, and a manually operable flush valve actuator. The manually operable flush valve actuator controls the discharge of water under pressure from the water vessel into the toilet bowl. Although some improvements were made in this invention, there are still some shortcomings as follows:
         1. The system only has the single flush function also and the refill rate is not adjustable.   2. A complicated cleaning device is required. To make the piston of the flush valve drop slowly enough to make the pressure water let out from the vessel completely, the annular section of the inlet of the flush valves must be as small as about 0.00078 inch 2  or 0.5 mm  2 ). A small opening like this is very easy to be blocked by impurities in the water supply. Therefore, a cleaning device needs to be attached, which complicates the structure.       

   Other partial flush systems have been implemented, but have not been implemented with a pressurized flushing system. The term partial flush refers to quantities that are less than a full flush. The term partial flush is not limited to fifty percent water volume of a full flush. 
   OBJECTS AND ADVANTAGES 
   The object of the invention is to provide a pressure assisted dual flush system for providing two different water discharge volumes. Accordingly, the advantages of such invention are:
         1. The present invention has dual flush function. The dual flush valve has two pistons. The top piston and bottom piston are set in the dual flush valve forming top chamber and bottom chamber. When partial tank flush is desired, for liquid waste for instance, the user needs only to discharge the pressurized water in the bottom chamber of the vessel by raising the bottom piston. In addition the user may discharge all the water in both the top and bottom chambers at the same time when a full tank flush is needed to discharge solid waste.   2. The present invention has a triple safety device, namely the stabilizing device in the refill valve and a double safety pressure relief device.   3. The control valve is also designed with dual flush function according to the dual flush valve and can be set independently from the system, to adapt with different assemble models.   4. The present invention has an excellent suitability and can be matched with all types of the toilet models. Because the control valve set is independent from the dual flush valve, the control valve can be set on any position of the ceramic water tank and can be easily matched with the front plate type, side plate type and the top plate type toilet tank.   5. The present invention has a self-lock piston, which stabilizes the total discharge water volume.   6. The suitability of the present invention can be seen from its adaptation to all kinds of toilet tanks with different water sealing requirements. The user can adjust the cross position between the through opening and the radial opening at the side wall of the bottom piston, to adjust the size of the sectional opening of the refill device. Thus, to adjust the refill volume to apply the present invention to various toilet bowl models.   7. The present invention has self-cleaning function. Since the inlet of the dual flush valve of present invention does not control the drop speed of the bottom piston, the diameter of the opening can be designed comparatively larger. In order to control the drop speed of the bottom piston, a guide slot is attached to the slide bar of the bottom piston. The radius of the guide slot is designed so as to control the descending speed of the bottom piston. During the actuation of the bottom piston, the fluid flows cleans the guide slot and is an additional feature of the invention.       

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is the outside view of the present invention, showing the whole device 
       FIG. 2  is the sectional view of present invention (not showing the control valve) 
       FIG. 3  is the stereoscopic diagrammatic sketch of the pressure water vessel 
       FIG. 4  is the stereoscopic decomposition diagram of the infill stabilizing valve 
       FIG. 5  is the sectional view of the infill stabilizing valve 
       FIG. 6  is the stereoscopic decomposition diagram of the air-in valve 
       FIG. 7  is the sectional view of the air-in valve 
       FIG. 8  is the stereoscopic decomposition diagram of the dual flush valve 
       FIG. 9  is the sectional view of the dual flush valve 
       FIG. 10  is the stereoscopic decomposition diagram of the dual flush control valve 
       FIG. 11  is the sectional view of the dual flush open valve 
       FIG. 12  is the diagrammatic sketch of the dual flush valve in the sealing state (not in function) 
       FIG. 13  is the diagrammatic sketch of the dual flush valve under half flush opening 
       FIG. 14  is the diagrammatic sketch of the dual flush valve under half tank refilling; 
       FIG. 15  is the diagrammatic sketch of the dual flush valve under full flush 
       FIG. 16  is the diagrammatic sketch of the dual flush valve under full tank refilling (section one) 
       FIG. 17  is the diagrammatic sketch of the dual flush valve under full tank refilling (section two) 
       FIG. 18  is the diagrammatic sketch of the dual flush control valve under half flush opening action 
       FIG. 19  is the diagrammatic sketch of the dual flush control valve 
       FIG. 20  is the diagrammatic sketch of the infill stabilizing valve under pressure discharging 
   

   SUMMARY OF THE INVENTION 
   A pressure assisted dual flush operating system in accordance with the present invention generally includes a vessel for receiving, containing and discharging pressurized water with the vessel having an outlet for discharge of water from the vessel. 
   An anti-siphon valve is provided which includes an airlet inlet for introducing water into the vessel and an inlet valve for admitting water to the anti-siphon valve. 
   A dual flush valve is provided for selectively releasing different quantities of water from the vessel through the vessel outlet and a control valve is provided for selecting one of the different quantities of water released by the dual flush valve. 
   Preferably, the vessel is sized for containment within a toilet tank and the control valve is disposed in fluid communication with the dual flush valve through flexible conduits in order to enable placement of the control valve anywhere on the toilet tank. This facilitates retrofitting the dual flush system in accordance with the present invention into existing toilets which have a toilet bowl equipped with a hydraulic jet. Thus, the control valve may be installed in a toilet tank through a front surface or a side surface as provided by the existing tank. 
   More specifically, the control valve includes a pivotable handle and two conduits interconnected with the dual flush valve along with a mechanism for hydraulically selecting one quantity of water to be released by the dual flush valve upon pivoting of the handle in one direction and hydraulically selecting another quantity of water to be released by the dual flush valve upon pivoting of the handle in an opposite direction. The selection of water to be released by pivoting of the handle may be reversed upon reversal of interconnection of the two conduits between the control valve and the dual flush valve. 
   Preferably, the dual flush valve is disposed within the vessel and the anti-siphon valve and the inlet valve are attached to the vessel. 
   The inlet valve and the siphon valve are in fluid communication with one another through a conduit disposed exterior to the vessel and a fluidic connection is provided between the control valve, the inlet valve, and the vessel outlet for directing overflow of water into the vessel outlet to reduce water accumulation in the toilet tank beneath the vessel. A gland may be provided for removing water from between the vessel and the toilet tank upon release of water through the vessel outlet. 
   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   As is shown in  FIG. 1  and  FIG. 2 , the invention includes the pressure water vessel A, the infill valve M, the air-in valve S, the dual flush valve F and the dual flush control valve C. The infill valve M is fixed in the lower left of the pressure water vessel A. The air-in valve S is fixed in the upper right of the pressure water vessel A The dual flush valve F is fixed through the middle of the pressure water vessel A. The dual flush control valve C can be installed in any position of a toilet tank (not shown in the Figs.), namely the either front side, side or top of the toilet tank as hereinabove noted. 
   The Pressure Water Vessel A (Please Refer to the  FIG. 1 to 3 ) 
   The pressure water vessel A is a sealed container made of high-strength and high-stability material. An opening A 1  is set above the center of vessel A with some projections around its brim. The outlet A 2  is set under the opening A 1  and some external threads are set in the peripheral lower section of the outlet A 2  to connect with the inlet of the toilet tank. A locating plate A 3  is set at the top of the outlet A 2 . An outlet A 4  is set under the locating plate A 3  and inside the upper section of the outlet A 2 , and its inner diameter is smaller than the diameter of the outlet A 2 . Conic surface A 5  is set above the outlet A 4 . In addition, the stabilizing outlet A 6  is set at the side of the upper section of the outlet A 2  responding to the outlet A 4 . The flush gland A 61  and the flush baffle A 62  are screwed with the stabilizing outlet A 6 . A cylinder locating hole A 7  is set in the lower left of the pressure water vessel A. The inlet A 8  is set in the upper right of the pressure water vessel A. The inlet A 8  is installed through the tank A forming an air and water mixed duct A 9  to improve intake effect. 
   The pressure water vessel A is installed inside the toilet tank and the water inlet of the toilet tank with the threaded portion of the outlet A 2 . The control valve C is in fluid communication with the dual flush valve F through flexible conduit T 1 , T 2  to enable placement of the control valve C anywhere on the toilet tank, not shown. A flexible conduit T 3  interconnects the air-in valve S with the influid valve M and conduit T 4 , T 5  provide a fluidic connection between the control valve C, inlet valve M and outlet A 2  for directing overflow water into the outlet A 2  to reduce water accumulated in the toilet tank (not shown) and vessel A. 
   The Infill Valve M (Please Refer to the  FIGS. 4 and 5 ) 
   As is shown in the  FIG. 4 , the infill valve M includes front cover M 1 , valve handle parts M 2 , valve body M 3 , valve support M 4  and rear cover M 5 . 
   The outlet M 11  is set in front of the front cover M 1 , while external thread is set behind the front cover M 1 . Several out gates M 13  are set around the middle section of the front cover M 1 . Valve handle parts M 2  include valve handle M 21 , valve handle spring M 22  and seal cover M 23 . Valve handle M 21  is a hollow trumpet shaped having flange M 211  in its front section where a seal component M 212  is set in front of flange M 211 . Seal cover M 23  is a disk at the center of which an opening M 231  for receiving the posterior segment of the valve handle M 21 . A seal component M 232  is set in a periphery of the seal cover M 23  and a seal component M 233  is set between the opening M 231  and the valve handle M 21 . 
   The valve body M 3  is a hollow cylinder with an internal thread M 31  in the front portion and an external thread M 32  in the rear portion. A seal component M 33  is set in the rear portion of the tread M 32 , and a baffle M 34  is set in between the front and rear portions. An opening M 35  is set in the center in of the baffle M 34 . 
   The valve support M 4  includes movable valve support M 41 , sealing plate M 42 , hold set M 43  and valve support spring M 44 . The movable valve support M 41  is a cylinder with a sealing plate M 42  in it, and the sealing plate M 42  is set in the movable valve support M 41  by the holding set M 43 . 
   The rear cover M 5  is an inverted L shaped hollow, with an internal thread M 51  set at front. A fixing pole M 52  is set inside the rear cover M 5  fixing the valve support spring M 44 . An inlet M 53  is set at the bottom of the rear cover with an external thread M 54  around, and a cross guide pole M 55  is set above the cover. 
   While assembling, please refer to  FIG. 5 , first slip the valve support spring M 44  on the fixing pole M 52  in the rear cover M 5 , then slip the sealing plate M 42  and the holding set M 43  in the valve support M 4  in turn, and push them to the other end of the value support M 44 . Then connect the valve body M 3  (with the seal component M 33 ) with the rear cover M 5  by screwing external thread M 32  with internal thread M 51 . 
   Then place the seal cover M 23  (with the seal components M 232  and M 233 ) into the front portion of the valve body M 3 , pushing it onto the baffle M 34 . Then set the handle M 21  (with the valve handle spring M 22 ) into the opening M 231  of the seal cover M 23 . Finally, screw the front cover M 1  onto the valve body M 3  to complete the assembly. 
   After assembly, fix the infill valve M onto the toilet water tank with the external thread M 54  at the bottom of the rear cover M 5 , connect it with the upper duct of the supply system, and set the cross guide pole M 55  into a locating opening M 7  at the bottom of the A, so that the valve M can be fix tight. Connect the outlet M 11  of the front cover M 1  with a hose and a hoop, then connect the hose with the infill duct S 2  of the air-in valve S described later in the next paragraph. 
   The Air-in Valve S (Please Refer to the  FIGS. 6 and 7 ) 
   As shown in  FIG. 6 , set in the body S 1  of the air-in valve S there are infill duct S 2 , anti-siphon valve S 3 , discharge duct S 4 , check valve S 5 , air-in valve S 6 , outlet S 7  supplying water to the dual flush valve F, and low pressure control valve S 9 . 
   The hose, or conduit, connection S 21  is set under the inlet duct S 2  with a seal component S 22  between them. 
   The valve S 3  is set on the duct S 2 , including the duct S 31  connected with the duct S 2 , having a sealed siphon ball S 32  fixed on the duct S 31  and the S 33  screwed on the duct S 31 . The air hole S 34  is set in the cover S 33  which diameter is smaller than the ball S 32 , and the seal components S 35  is set in the junction between the cover S 33  and the body S 1 . 
   The outlet S 43  is set under the duct S 4 , and a fixed disk S 11  is set on the bottom of the duct S 4  in which an air spout S 8  is set. A neck portion S 81  is set under the spout S 8  forming a ring chamber S 41  in between the neck portion S 81  and the inwall of the duct S 4 . A seal component S 82  is set between the spout S 8  and the duct S 4 . A valve cover S 42  is fixed at the top of the duct S 4 , above the spout S 8 . 
   A control valve S 9  is set between the cover S 42  and the air spout S 8 , which includes valve support S 91 , filler plug S 92  and spring S 93 . A seal component S 44  is set between the support S 91  and the duct S 4 . The filler A 92  moves up and down inside the support S 91  where a seal component S 94  is set between them. A seal component S 95  is set under the block S 92  and the block S 92  is fixed above the neck portion S 81  inside the spout S 8  while the seal component S 95  is being pushed by the spring S 93 . 
   The check valve S 5  is set between the infill duct S 2  and the outlet duct S 4  above the neck portion S 81 , which includes a sealed ball S 52  and a channel S 51  respectively connecting with the ducts S 2  and S 4 . The channel S 51  is echeloned upon the sealed ball S 52 . The diameter of the echeloned end connecting with the duct S 2  is comparatively smaller then the other end. 
   The air-in valve S 6  is set above the duct S 4  and is located in the ring chamber S 41 . Similar to the valve S 3 , the air-in valve S 6  also includes a channel S 61  connecting with the duct S 4 , a sealed ball S 62  limited in the channel S 61 , and a cover S 63  fixed on the duct S 61 . An inlet S 64  with smaller diameter than the ball S 62  is set above the cover S 63 . A seal component S 65  is set in the screwed junction of the cover S 63  and the body S 1 . The valve S 6  also provides for back flow protection to the inlet valve M in order to prevent contaminated water from being pulled back into the inlet valve and a water supply (not shown) connected thereto. 
   In addition, an outlet S 7  is set in the outlet duct S 4 , behind the check valve S 5  and in front of the spout S 8 . The outlet S 7  is able to supply water to the dual flush valve F. 
   While assembling, referring to  FIG. 7 , firstly connect the hose with hose junction S 21  under the duct S 2 , and then set the sealed ball S 32  into the channel S 31  while having the cover S 33  screwed above it. Then set the seal ball S 52  into the channel S 51  through the outlet S 7 , and inset the spout S 8  through the upper side of the duct S 4 . Then set control valve S 9  above the spout S 8 , pushing the seal component S 95 , under the block S 92 , upon the upper portion of the neck portion S 81 , and screw on the cover S 42 . Finally set the sealed ball S 62  into the channel S 61 , and screw on cover S 63 . 
   The fixed disk S 11  of the valve S is screwed with the inlet of the vessel A, where the outlet S 43  is matched with the inlet A 8  of the vessel A with the seal component S 12  in the junction. The hose junction S 21  of the duct S 2  is connected with the hose in the outlet M 11  of the inlet valve M. The outlet S 7  is connected with the inlet  13  of the dual flush valve F (described below) by a hose. 
   The Dual Flush Valve F (Please Refer to  FIGS. 8 and 9 ) 
   As shown in  FIG. 8 , the dual flush valve F includes valve body  1 , upper cylinder sleeve  2 , upper piston  3 , one-way valve  4 , self-lock piston  5 , lower cylinder sleeve  6 , lower piston  7 , and refill device  8 . 
   A protrusion  15  with the seal component B 1  and four adequate distribution sockets  16  is set around the valve body  1 . There is some reserved space between the protrusion  15  and the sockets  16 . The valve body  1  is hollow shaped above which a full flush outlet  11 , a partial flush outlet  12  and an inlet  13  are set. 
   The full flush outlet  21  is set on top of the upper cylinder sleeve  2  connecting with the full flush outlet  11  of the valve body  1 . A half outlet  22  is set in the middle of the upper cylinder sleeve  2  connecting with the half outlet  12  of the valve body  1 . A ring locating protrusion  24  is set at the bottom of the sleeve  2 , having a depression  25 . 
   A cup body  31  is set on the top of the upper piston  3 , where there is a seal components E 1  around the top of the cup body and a through opening  311  is located at the bottom of it. A tubular body  32  is set at the bottom of the top piston  2  connecting to the cup body  31  by a connecting rib  33 , where there is a seal components E 2  around the top of the tubular body and a through opening  321  is located at the wall of the tubular body. In addition, an inner flange  322  is set above the through opening  321  inside the tubular body  32  and a fine slot  323  is set inside the inner flange  322 . 
   The one-way valve  4  includes spool  41 , valve support  42  and one-way valve spring  43 . The support  42  is fixed inside the tubular body  32  of the upper piston  3 . The spool  41  is set inside the support  42 . A seal component  44  is set at the bottom of the spool  41  while the two ends of the spring  43  are linked onto the support  42  and the spool  41  respectively. 
   The self-lock piston  5  is set in the tubular body  32  of the upper piston  3 . A support  51 , which can be fixed on the tubular body  32 , is set at the bottom of the tubular body  32 . A through opening  511  is set on the support  51 . A shaft  52  is located above the piston  5  while a seal component  53  is linked around it. In addition, two absorption magnetic elements  54  and  55  are respectively set at the bottom of the piston  5  and at the top of the support  51 . 
   A seal component B 2  is set around the lower cylinder sleeve  6 , while a layer baffle  61  is located inside the sleeve. The baffle  61  has at least one on-way valve  62 , while an opening  63  is set on the baffle  61 . 
   A seal component E 2  is set around the lower piston  7 . A slide bar  71  is set above the piston  7  as the bar goes through the opening  63  on the baffle  61  while a seal component E 4  is set between them. The slide bar  71  includes refill slot  711 , partial flush slot  712  and full flush slot  713 . The radiuses of both the refill slot  711  and the full flush slot  713  are comparatively smaller then the half flush slot  712 . An adjustable bolt  714  is set at the top of the bar  71 . A protrusion  73  is located at the bottom of the slot  72 . Two seal components B 3  and E 5  are set at the top and the bottom of the protrusion  73  respectively. 
   The refill device  8  is set in and under the protrusion  73  of the piston  7 , where it is hollow inside the protrusion  73 . A radial hole  731  is located on the side wall of protrusion  73 . The refill device  8  includes an adjustable support  81  and an adjusted bar  82 . The support  81  is cylinder and set inside the protrusion  73  having an opening  811  opposite to the radial hole  731  of the protrusion  73 . The adjusted bar  82  is set in the support  81  and a filler plug  821  is set in therewith, and blocks the hole  811  while connecting with the axis hole of the support  81 . 
   While assembling, please refer to  FIG. 9 , set the piston  5  into the tubular body  32  of the piston  3  from the bottom, fix the support  51  on it, and make the shaft  51  go through the support  511  of the support  51  outside the tubular body  32  in order to limit the tubular body  32  in the piston  5 ; then fix the spool  41  in the cup body  31  from the top and the opening  311  at the bottom of the cup body  31  is blocked by the seal component  44  of the spool  41  with the pushing of the spring  43 ; after that, set the assembled upper piston  3  in the sleeve  2  and set the reset spring D between the sleeve  2  and the cup body  31 , so the piston  3  can be moved up and down in the sleeve  2 . A seal top chamber E 1  is set between the cup body  31  and the upper section of the sleeve 2 , forming an area F 1  between the body  31  and the sleeve  2 ; then set the sleeve  6  in the piston  7  from its bottom and make the shaft  71  above it while connecting through the opening  63  of the baffle  61  in the sleeve  6 . Finally, set the sleeve  2  in the body  1 , and match the outlet  21  and the outlet  22  with the outlet  11  and the outlet  12  of the body  1  respectively, then fix the sleeve  6  at the bottom of the body  1 , and fix protrusion  24  of the sleeve  2  in between to tighten the sleeve 2 . The piston  7 , the sleeve  6  and the sleeve  2  form an area F 2  where F 2  is divided into three chambers, by the piston  5  and the baffle  61 , the F 21 , the F 22  and the F 23 . 
   After the assembly of the dual flush valve F is completed, set the opening A 1  of the vessel A in the toilet tank and make the bottom of the sleeve  6  fixed the locating plate A 3  inside the vessel A. 
   Turn the valve F by 40 degrees to connect the sockets  16  of the valve F to the opening A 1  of the vessel A. After assembling the valve F, 
   The seal component B 3  of the lower piston  7  is set right upon the conic surface A 5  of the vessel A. The bar  82  of the refill device  8  is extended to its maxima position by the A 21  in the outlet A 2  of the vessel A, matching the opening  811  to its axis hole. In addition, the inlet  13  matches to the outlet S 7  of the valve S by a hose. The outlets  11  and  12  are respectively connected with the inlets C 12 ′ and C 12  on the ceramic water tank. 
   The outlets  11 ,  12  and  13  described above are joined through the hose junction to achieve a quick and simple assembly. Bayonet lock is the practical method of connection. 
   As outlet  11  as example: two L shaped slots  111  ( FIG. 8 ) are set inside the outlet  11 , while two protrusions  171  are set in the junction  17  matching to the slots  111 . There is an additional spanner  172  set in the junction  17 . While assembling, connect the protrusion  171  of the junction  17  to the L-shaped slots  111  of the outlet  11 , then press down and turn the junction  17  until the protrusions  171  lock with the L-shaped slot  111  of the outlet  11 . Then connect the junction  17  with a hose. This method is quick and simple, which also may apply to other devices (for example, the air-in combination  5 ) while connecting the outlet or the inlet with the hose. 
   The Dual Flush Control Valve C (Please Refer to  FIGS. 10 and 11 ) 
   As shown in  FIG. 10 , the dual flush control valve C includes a body C 1 , having two chambers C 11  and C 11 ′, two inlets C 12  and C 12 ′ respectively located in the bottom of the chambers, two protrusions C 13  and C 13 ′ rounded the inlets C 12  and C 12 ′ having internal threads for connecting with hose junction, two covers C 18  and C 18 ′ screwed at top of the chambers C 11  and C 11 ′, two outlets C 15  and the C 15 ′ are set at the bottom of chambers C 11  and C 11 ′, a radial chamber C 14  set between and through the chambers C 11  and the C 11 ′, having a threaded protrusion C 16  where the protrusion C 16  has an opening C 17  connecting to the side of the chamber C 14 , and a cover C 19  screwed on the chamber C 14  having a seal component C 72  set in between. 
   A cylinder full flush filler plug C 3  and a cylinder half flush filler plug C 3 ′ are respectively set inside the chambers C 11  and C 11 ′, having openings C 31  and C 31 ′ at the side of the plugs C 3  and C 3 ′. Protrusions C 32  and C 32 ′ are set at the bottom of the plugs, connecting with the inlets C 12  and C 12 ′ of the chambers C 11  and the C 11 ′. Seal components C 33  and C 33 ′ are respectively placed at the bottom of the protrusions C 32  and C 32 ′, while protrusions C 71  and C 71 ′ are placed in between the plugs and the chambers. In addition, springs C 4  and C 4 ′ are set in between the plugs (C 3  and C 3 ′) and the covers (C 18  and C 18 ′). 
   Baffles C 10  and C 10 ′ are fixed in the chambers C 11  and C 11 ′ above the outlets C 15  and C 15 ′, having openings C 10  and C 101 ′. Openings C 101  and C 10 ′ connect through the protrusions C 32  and C 32 ′ of the plugs C 3  and C 3 ′. One-way valves C 8  and C 8 ′ are covered around the protrusions C 32  and C 32 ′, located inside the baffles C 11  and C 11 ′. In addition, slots C 321  and C 321 ′ are set on the protrusions C 32  and C 32 ′. 
   The chamber C 14  comprises a deflector rod C 5 , where the rod C 5  comprises protrusion C 51  matching the openings C 31  and C 31 ′ of the plugs C 31  and C 31 ′. Rod C 5  is designed to plug into the opening C 17  of the body C 1 , and has square plug C 52  on it. The plug C 52  has a locking slot C 53  at the end of the plug C 52 . A control handle C 6  is connected in the end of the protrusion C 16 , having a locking hook C 61  on the side. 
   To assemble the dual flush control valve C, refer to the  FIG. 11 , set the plugs C 3  and C 3 ′ respectively in the chambers C 11  and C 11 , connecting the protrusions C 32  and C 32 ′ through the openings C 101  and C 101 ′ of the baffle C 10  and C 10 ′, then place the springs C 4  and C 4 ′ on the protrusions, and screw on the covers C 18  and C 18 ′. With the plugs C 3  and C 3 ′ being pushed by the springs C 4  and C 4 ′, the protrusions C 32  and C 32 ′ are tightly connected to the inlets C 12  and C 12 ′ with seal components C 33  and C 331  in between. After that, insert the far end of the rod C 5  into the opening C 17  of the body C 1 , matching the protrusion C 51  to the openings C 31  and the C 31 ′ of the plugs C 3  and C 3 ′, then screw on the cover C 19  to fix the rod C 5  in the chamber C 14 . 
   After the assembly completed, the dual flush control valve C can be installed on the front plate or the side plate of the ceramic water tank. The detailed method of installation is to insert the protrusion C 16  through the opening of the ceramic water tank and tighten it on the ceramic water tank with pads C 21  and C 22 . Then install the handle C 6  from other side of the tank by connecting the locking hook C 61  with the opening C 52  of the rod C 5 , locking it into the slot C 53  to make the rod C 5  simultaneously corresponding with the handle C 6 . Finally connect the inlets C 12  and C 12 ′ with the outlets  12  and  11  of the valve F by a hose. 
   Operation of the Perferred Embodiment 
   As shown in  FIG. 2 , because the pressure in the pressure water vessel A is low, the pressure water in the supply system can smoothly fill from the supply inlet M 53  of the inlet valve M into the outlet M 11 . The pressure water fill in the duct S 2  of the S through the hose, the pressure close the S 32  and push aside the S 52  at the same time. When the pressure water flows through the spout S 8 , the piston S 92  would be pushed through and divides the water flow into two ways as one out of the outlet S 7  and the other into the neck portion S 81 . When the water goes through the S 81 , the water forms a high speed water column and makes the chamber S 41  vacuum seal around the S 81  because of its smaller sectional area. With the sealed ball S 62  pushed aside by the pressure, the air is allowed to flow in and out from the outlet S 43 . The air and water would be fully mixed in the tube A 9  of the vessel A. 
   At the same time, the water flows through the hose from the outlet S 7  then replenish into the valve F through the inlet  13 . This flow of water pressure fills valve F including the chambers F 1  and F 2  therefore closing valve F. When the pressure in the supply system is too low (lower than 6 psi), the pressure would not be able to push the piston S 92  aside, so that the pressure water would only be able to flow in the valve F from the outlet S 7  closing the piston  7 . Without the valve S 9 , when the pressure is lower than 6 psi, since the water pressure continues to fill in the inlet of the valve A and fills into the toilet tank from the outlet A 4 , the tank would leak. 
   The air-water mixture continuously fills into the water vessel A, the pressure in the water vessel A rises, so that the water&#39;s speed in the valve S drops down and so does the vacuum degree around the water column of the S 8 . At the same time, the pressure in the water vessel A transmits to the inlet S 64  closing the sealed ball S 62 , but the water still continues to fill in the water vessel, until the pressure in the water vessel A is balanced with the inlet pressure while reaching the preset pressure balance. 
   As shown in  FIG. 12 , when the pressure in the water vessel A reaches the preset pressure balance, the pressure inside and outside the valve F are in balance while the pressure level outside and inside piston  7  is also the same. Since the area inside the piston  7  is larger than the area outside, the downward pressure on the piston  7  is greater than the upward pressure, making the seal component B 3  tighten (or seal) upon the A 5  of the outlet A 4 . 
   While the pressure in the vessel A passes through the valve S to the outlet M 11  of the valve M, the handle M 21  suffers this opposite pressure, overcoming the push from the spring M 22 , and then pushes the valve handle onto the port, reaching the seal plate M 42  of the support M 41  to shut off the water inlet. 
   When making the partial flush also called a half flush, please refer to  FIG. 18 , turn the handle C 6  of the valve C upward to turn the rod C 5  clockwise, lift the piston C 3  up, lifting the seal component C 33  away from the corresponding inlet C 12 . Because it is connected with the outlet F 12  of the valve F, the pressure water in the chamber F 2  of the valve F will fill in the space under the baffle C 10  of the chamber C 11 , and fill in the space between the pressure water vessel A and the toilet water tank, from the outlet C 15 . At this time, the piston C 3  moves upward to form a negative pressure to open the valve C 8 , causing part of water fill into the chamber above the baffle C 10 . When the handle C 6  being released, the spring C 4  will push the piston C 3  downward and the pressure water in the chamber above the baffle C 10  will shut off the valve C 8  (referred to  FIG. 19 ). As a result, the pressure water can only fill downward along the slot C 321  of the protrusion C 32 . Since radius of the slot C 321  is so narrow, the piston C 3  moves down very slowly, achieving the time delay purpose. Therefore it allows the pressure water in the valve F to be discharged completely, and avoid the possible outlet obstruct which could cause piston  7  to turn off prematurely, which would affect the total discharge volume. 
   Then refer to  FIG. 13 , after the pressure water in chamber F 21  being discharged, the pressure in the chamber F 2  drops. The pressure water in the chamber F 23  will push aside the valve  62 , flowing into the chamber F 22  quickly, then fill toward the chamber F 21  through the opening  321  in the tubular shaped body  32  of the piston  3 , finally letting out from the dual flush valve. At this time, the pressure above the piston  7  drops quickly, and the water in the vessel A pushes the piston  7  upward to open the outlet A 4 . The pressure water in the vessel A will fill into the toilet bowl from the outlet A 4  through the outlet A 2 . The partial flush begins at this time while the pressure in the vessel A drops at the same time. 
   When the piston  7  moves upward, it pushes the piston  5 , moving it upward while it overcomes the attraction from of the absorption magnetic elements  54  and the  55 . The seal component  53  above the piston  5  pushes upon the protrusion  322  in the tubular body  32  of the piston  3 , forming a closure. Because there is still pressure in the chamber F 1 , the piston  3  is not able to move upward, furthermore prevents the piston  7  from moving upward. At this time, the position where piston  7  is located just makes the slot  712  of the bar  71  be located on the seal component E 4  in the opening  63  in the baffle  61 . In addition, because the pressure in the vessel A drops, the pressure water continuously fills into the vessel A through the valve S from the valve M, while replenishing the pressure water into valve F at the same time. The pressure water flows into the chamber between the body  1  and the sleeve  2  from the inlet  13  of the body  1 , then flows into the sleeve  6  from the slot  25  in the protrusion  24  of the sleeve  2  (the piston C 3  of the valve C has now shut off), to make the pressure in the F 22  rise. 
   The pressure water will close the valve  62 , therefore the water in the chamber F 22  can only fill into the chamber F 23  through the slot  712  in the bar  71  of the piston  7 . With the large radius of the slot  712 , the water can flow into the chamber F 23 . The piston  7  moves downward very quickly, until partial water volume in vessel A is released as shown in  FIG. 14 . 
   In  FIG. 14 , the opening  63  of the baffle  61  is corresponding to the slot  711  in the bar  71  of the piston  7 , and the seal component E 5  under the protrusion  73  will block the outlet A 4  of the vessel A. The water in the vessel A is not able to flow into the toilet bowl as the partial flush completes. When the piston  7  moves downward, the A 21  in the outlet A 2  will push the bar  82 , connecting the opening  811  of the support  81  with its opening. When the water in the vessel A flows through the opening  731  at side of the protrusion  73  and fills into the toilet bowl from the axis hole of the support  81 , the partial refill begins. The opening  63  of the baffle  61  corresponds with the slot  711  of the bar  71  and the radius of the slot  711  is very narrow, only a small amount of water is able to flow into the chamber F 23  from the F 22 , where as the piston  7  moves downward slowly until it is closed before the full flush (As shown in the  FIG. 12 ). The water in the A flows through the inlet device  8  into the toilet bowl in this process, forms a water tight seal. 
   During the above process, part of water in the chamber F 22  flows through the tubular body of slot  323  in the protrusion  322  of the tubular body  32  of the piston  3  into the chamber F 21  until the pressures below and above the piston S are in balance, and opens the piston S by both gravity and the magnetic element&#39;s absorptive force, forming the original closure status as shown in  FIG. 12 . 
   When the full flush is desired, push downward on the handle C 6  of the valve C, making the C 5  anti-clockwise to open the valve C 3 ′ (the steps here are the same as the process describe above). Because the valve is connected with the outlet  11  of the valve F, the pressure water in the chamber F 1  of the valve F will be forced out from the outlet C 15 ′. As shown in the  FIG. 15 , the pressure above the piston  3  (the pressure in the top chamber F 1 ) will drop sharply, the valve  4  will be pushed open by the pressure in the chamber F 2 . Then the pressure water of the F 2  will flow through the chamber F 1  then flows out from the outlet  21 , opening the outlet A 4  in the vessel A, providing a full flush. The discharging process of the pressure water in the chamber F 2  is the same as above. Some differences are: because both the piston  3  and the piston  7  move upward at the same time, the piston  7  rises higher then piston  3  until it reaches the preset position shown in  FIG. 15 . Now, the piston C 5 ′ of the valve C is closed, while water continuously fills into the valve F raising the pressure in the valve F. After the water in the valve F flows into the chamber F 22 , the pressure will close the valve  62 , therefore the water can only flows through the slot  713  into the chamber F 23  (At this time, the seal component E 4  of the opening  63  in the baffle  61  matches to the slot  713  in the bar  71  of the piston  7 ). Because the radius of the  712  is very narrow, very little water would fill into the chamber F 23 , dropping the  7  very slowly. It can make the reset time of the piston  7  longer, discharging the water in the vessel A completely, whereas the full flush is completed (As shown in the  FIG. 6 ). After the full flush is completed, the slot  713  in the bar  71  of the piston  7  still matches to the seal component E 4  of the opening  63  in the baffle  61 . The piston  7  still drops slowly. Now, after the water in the vessel A continuously flows into the toilet bowl and remains there, forming water tight seal, the first refill is completed. 
   When the slot  713  in the bar  71  of the piston  7  is responding to the seal component E 4  of the opening  63  in the baffle  61 , the piston  7  will move downward quickly to the position shown in  FIG. 17 , meaning the seal component E 5  under the protrusion  73  of the piston  7  blocks off the outlet A 4 , as the second refill begins. The process is the same as the partial flush described herein. 
   While the first refill and the second refill, the self-locking piston  5  opens, when open process is the same as the process in the partial refill. 
   Additionally, the stabilizing outlet A 6  is set at side of outlet A 2  in the vessel A in the present invention, which is used to discharge the stabilizing water between the A and the ceramic water toilet tank. Because the flush cover A 61  and the flush baffle A 62  are screwed on the stabilizing outlet A 6 , when the pressure water vessel discharges, the baffle A 62  is tightened upon the cover A 61  under the water pressure, the pressure water won&#39;t be discharged. After the full flush is over, the stabilizing inlet water would push aside the cover A 62  and flows into the toilet bowl. 
   Triple Safeguard 
   Additionally, the pressure water vessel A works in a sealed status, it would be dangerous if the pressure is allowed to get too high, so as the pressure is limited within a preset range. The invention comprises a triple safeguard: 
   1. The Infill Valve M 
   Please refer to  FIG. 20 . If a blockage makes M unable to complete the water&#39;s filling (for example, a blockage between the M 21  and the M 42 ), the pressure in the vessel A will continue rising, causing the increasing inverse pressure of the valve handle M 21  to overcome the push of the spring M 44  in the support M 41  until it reaches the preset pressure limit. Then the protrusion M 211  of the handle M 21  will move downward to the outlet M 13  in the cover M 1  to open the cover M 13 . Then the water in the A will flow out from the outlet M 13  until the pressure drop to the preset working pressure, then the water will be rerouted and flows into the baffle between the vessel A and the ceramic toilet water tank, then the water will flow directly into the toilet bowl from the outlet A 6 . 
   2. The Double Safeguard of the Dual Flush Control Valve C. 
   The pistons C 3  and C 3 ′ of the valve C are connected to the water pressure in the valve F, and the pressure inside of the valve F is equal to the pressure inside the vessel A. Therefore, when the pressure in the vessel A reaches a certain level, the water pressure in the valve F will push the protrusions C 32  and C 32 ′ of the pistons C 3  and C 3 ′ to push them away from the seal surface causing them to open, so that the valve F begins the full flush or the partial flush to achieve the discharging protection. The control valve C has two filler plugs, C 3  and C 3 ′, if one of the two is out of work, the other is provided as back up and an additional safeguard. 
   The third safeguard is: if the pressure in the vessel A is for whatever higher than the working pressure, the valve M begins discharging protection; when the valve M is not working or other factors allow the pressure in the vessel A continue to rise, the C 3  or C 3 ′ of the piston C will cause the partial flush or the full flush valve of the system and allow the pressure to be discharged completely to provide additional protection. 
   Although there has been hereinabove described a specific pressurized dual flush system in accordance with the present invention for the purpose of illustrating the manner in which the invention may be used to advantage, it should be appreciated that the invention is not limited thereto. That is, the present invention may suitably comprise, consist of, or consist essentially of the recited elements. Further, the invention illustratively disclosed herein suitably may be practiced in the absence of any element which is not specifically disclosed herein. Accordingly, any and all modifications, variations or equivalent arrangements which may occur to those skilled in the art, should be considered to be within the scope of the present invention as defined in the appended claims. 
   CALL OUT LIST OF ELEMENTS 
   Pressure Water Vessel A 
   
       
       Opening A 1   
       Outlet A 2   
       Locating Plate A 3   
       Outlet A 4   
       Conic Surface A 5   
       Stabilizing Outlet A 6   
       Flush Gland A 61   
       Flush Baffle A 62   
       Stabilizing Outlet A 6   
       Cylinder Locating Hole A 7   
       Inlet A 8   
       Air and Water Mixed Duct A 9 
 
Infill Valve M
 
       Front Cover M 1   
       Valve Handle Parts M 2   
       Valve Body M 3   
       Valve Support M 4   
       Rear Cover M 5   
       The Outlet M 11   
       Out Gate M 13   
       Valve Handle M 21   
       Valve Handle spring M 22   
       Seal Cover M 23   
       Flange M 211   
       Seal Component M 212   
       Opening M 231   
       Seal Component 
       Internal Thread M 31   
       External Thread M 32   
       Seal Component M 33   
       Baffle M 34   
       Pole M 35   
       Movable Valve Support M 41   
       Sealing Plate M 42   
       Hold Set M 43   
       Valve Support Spring M 44   
       Internal Thread M 51   
       Fixing Pole M 52   
       Inlet M 53   
       External Thread M 54   
       Cross Guide Pole M 55 
 
Air-in Valve S
 
       Body S 1   
       Air-in Valve S 
       Infill Duct S 2   
       Anti-Siphon Valve S 3   
       Discharge Duct S 4   
       Check Valve S 5   
       Air-in Valve S 6   
       Outlet S 7   
       Low Pressure Control Valve S 9   
       Hose Junction S 21   
       Infill Duct S 2   
       Seal Component S 22   
       Duct S 31   
       Sealed Siphon Ball S 32   
       Cover S 33   
       Air Hole S 34   
       Seal Components S 35   
       Outlet S 43   
       Duct S 4   
       Fixed Disk S 11   
       Air Spout S 8   
       Neck Portion S 81   
       Ring Chamber S 41   
       Seal Component S 82   
       Valve Cover S 42   
       Control Valve S 5   
       Valve Support S 91   
       Filler Plug S 92   
       Spring S 93   
       Seal Component S 44   
       Filler A 92   
       Seal Component S 95   
       Channel S 51   
       Sealed Ball S 52   
       Air-in Valve S 6   
       Channel S 61   
       Sealed Ball S 62   
       Cover S 63   
       Inlet S 64   
       Seal Component S 65   
       Outlet S 7   
       Spout S 8 
 
Dual Flush Valve F
 
       Valve Body  1   
       Upper Cylinder Sleeve  2   
       Upper Piston  3   
       One-Way Valve  4   
       Self-Lock Piston  5   
       Lower Cylinder Sleeve  6   
       Lower Piston  7   
       Refill Device  8   
       Protrusion  15   
       Seal Component B 1   
       Distribution Sockets  16   
       Full Flush Outlet  11 , 
       Half Flush Outlet  12   
       Inlet  13   
       Full Flush Outlet  21   
       Half Outlet  22   
       Ring Locating Protrusion  24   
       Depression  25   
       Cup Body  31   
       Seal Components E 1   
       Opening  311   
       Tubular Body  32   
       Connecting Rib  33 , 
       Seal Component E 2   
       Opening  321   
       Inner Flange  322   
       Fine Slot  323   
       One-Way Valve  4   
       Spool  41   
       Valve Support  42   
       One-Way Valve Spring  43   
       Support  42   
       Seal Component  44   
       Self-Lock Piston  5   
       Support  51 , 
       Opening  511   
       Shaft  52   
       Seal Component  53   
       Absorption Magnetic Element  54   
       Absorption Magnetic Element  55   
       Seal Component B 2   
       Layer Baffle  61   
       One-Way Valve  62   
       Opening  63   
       Seal Component E 2   
       Slide Bar  71   
       Seal Component E 4   
       Refill Slot  711   
       Half Flush Slot  712   
       Full Flush Slot  713   
       Adjustable Bolt  714   
       Protrusion  73   
       Seal Components B 3  and E 5   
       Refill Device  8   
       Radial Hole  731   
       Adjustable Support  81   
       Adjusted Bar  82   
       Opening  811   
       Filler Plug  821 
 
Dual Flush Control Valve C
 
       Body C 1   
       Chambers C 11  and C 11 ′ 
       Inlets C 12  and the C 12 ′ 
       Protrusions C 13  and C 13 ′ 
       Covers C 18  and C 18 ′ 
       Outlets C 15  and C 15 ′ 
       Radial chamber C 14   
       Threaded protrusion C 16   
       Opening C 17   
       Cover C 19   
       Seal component C 72   
       Cylinder Full Flush Filler Plug C 3   
       Cylinder Half Flush Filler Plug C 3 ′ 
       Openings C 31  and C 31 ′ 
       Protrusions C 32  and C 32 ′ 
       Inlets C 12  and C 12 ′ 
       Seal Components C 33  and C 33 ′ 
       Protrusions C 71  and C 71 ′ 
       Springs C 4  and C 4 ′ 
       Baffles C 10  and C 10 ′ 
       Openings C 101  and C 101 ′ 
       One-Way Valves C 8  and C 8 ′ 
       Slots C 321  and C 321 ′ 
       Deflector rod C 5   
       Protrusion C 51   
       Square Plug C 52   
       Locking Slot C 53   
       Control Handle C 6   
       Locking Hook C 61

Summary:
A pressure assisted dual flush operating system includes a vessel for receiving, containing and discharging pressurized water and an outlet for discharge of water from said vessel. An anti-siphon valve includes an air inlet for introducing water into said vessel and an inlet valve is provided for admitting water to the anti-siphon valve. A dual flush valve selectively releases different quantities of water from said vessel through the vessel outlet and a control valve selects one of the different quantities of water released by the dual flush valve.