the following descriptions are of exemplary embodiments only , and are not intended to limit the scope , applicability or configuration of the invention in anyway . rather , the following description provides a convenient illustration for implementing exemplary embodiments of the invention . various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims . referring to fig2 , 3 , 4 , 5 , 6 , 7 a , 7 b , and 7 c , a preferred embodiment of the present invention is comprised of a valve body 10 , a balance valve 20 , a ceramic cartridge 30 , a sleeve 40 , a fixation nut 50 and a balance valve seat 60 . wherein , the valve body 10 is provided with a cold water inlet 11 , a hot water inlet 12 , a water outlet 13 and a drain 14 all connected through a central trough 15 of the valve body 10 . the balance valve seat 60 has an outer diameter which is the same as an inner diameter of the central trough 15 and is directly placed in the central trough 15 . an accommodation trough 61 is provided on one side of the balance valve seat 60 to receive the balance valve 20 ( a member of the prior art ) comprised of a fixed part 21 and a movable part 22 ; a cold waterway 62 , a hot water way 63 and a water outlet way 64 are provided on the end surface of the balance valve seat 60 with both of the cold and hot water ways 62 , 63 being connected through the accommodation trough 61 . the ceramic cartridge 30 , also a member of the prior art , is provided at its bottom with a cold water inlet , a hot water inlet and a water outlet and contains a current mixing mechanism ; and rod extending from its top being connected to a handle to directly have the ceramic cartridge 30 mounted on the balance valve seat 60 , covered with the sleeve 40 and secured in the central trough 15 of the valve 10 . furthermore , the fixation nut 50 is screwed to the central trough 15 of the valve body 10 before being screwed to the other end of the sleeve to complete the assembly of the entire valve body . wherein , both of the cold and hot water ways 62 , 63 of the balance valve seat 60 are respectively connected at their lower ends to both of the cold d hot water inlets 11 , 12 of the valve body while their upper ends are respectively connected to cold and hot water inlets of the ceramic cartridge 30 . the water outlet way 64 of the balance valve seat 60 is connected at its top to the water outlet of the ceramic cartridge 30 and its lower end , to the water outlet 13 of the valve body 10 so that cold and hot water have to first flow through the balance valve seat 60 to undergo regulation and control of closing or opening the cold and hot water ways of the balance valve 20 ( in a way in consistency to the prior art ) before entering into cold and hot water inlets of the valve body 10 where both cold and hot water are mixed at a proper ratio by turning the handle and delivered to the water outlet 13 of the valve body 10 through the water outlet way 64 of the balance valve seat 60 . furthermore , as illustrated in fig8 and 9 , the specification of the valve body 10 can be standardized due to the installation of the balance valve seat 60 of the present invention , thus is also applicable for the assembly with a general cartridge . it will be understood that each of the elements described above , or two or more together may also find a useful application in other types of methods differing from the type described above . while certain novel features of this invention have been shown and described and are pointed out in the annexed claim , it is not intended to be limited to the details above , since it will be understood that various omissions , modifications , substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention .