Patent ID: 8202419

Claim:
In a tank for appliances which use filtered water with a seal for, for connection of a filter cartridge or a gravimetrically operated filter cartridge wherein the improvement comprises a tank mating connection on the tank outlet for mating with a filter mating connection on the filter cartridge, the tank mating connection having a combined polygonal coding and angular sealing surface disposed on the outlet inside the tank to form a polygonal coding and angular sealing filter connection to match a complementary combined polygonal coding and angular sealing surface disposed on the filter cartridge wherein a seal having a polygonal angular shaped circumference is formed by the interlocking of the combined polygonal coding and angular sealing surface on the tank mating connection and the complementary combined polygonal coding and angular sealing surface disposed on the filter cartridge, in order to preclude operation of the seal and use of a filter cartridge which does not correspond with said combined polygonal coding and angular sealing surfaces on said tank mating connection.