A mixer valve (10) includes a valve housing (12) that mounts a cartridge (26). The cartridge (26) houses a ball valve element (24) that has its lower end exposed to cooperate with seal elements (25) about inlet ports (18) and (19). The ball valve element is vertically affixed within the cartridge housing...http://www.google.com.au/patents/US5615709?utm_source=gb-gplus-sharePatent US5615709 - Mixer valve having a ball valve element housed in a cartridge
