the valve cartridge 26 is provided and includes a first and second rotatable disk 50 52 a first second and third stationary disk 54 56 58 and a first and second disk driver 60 62 the first and second rotatable disks 50 52 are generally cylindrical members and include a pair of ears 68 extending from an outer edge thereof the first rotatable disk 50 includes first and second bore 64 h 66 c while the second rotatable disk 52 similarly includes a first and second bore 64 c 66 h the first bores 64 h 64 c include a generally arcuate surface 70 disposed opposite a straight or planer surface 72 whereby the arcuate surface 70 cooperates with the straight surface 72 to form the shape of a semicircular aperture the second bores 66 c 66 h are formed adjacent the first bores 64 c 64 h and include an arcuate surface 74 formed between a pair of straight surfaces 76 as best shown in fig3 the pair of straight surfaces 76 cooperate with the arcuate surface 74 to form a generally quartercircular or triangular shaped aperture the first second and third stationary disks 54 56 58 each include a generally circular main body 78 a pair of flanges 80 and a pair of bores 82 c 82 h the flanges 80 extend from the main body 78 and serve to form a pair of recesses 84 therebetween as best shown in fig3 the recesses 84 engage arms 30 32 to align the first second and third stationary disks 54 56 58 with the valve body 12 and prevent rotation therebetween specifically the recesses 84 receive the first.