1
Clack Willis E, Kay Clifford, Nygren Charles E: Water softening systems. Clack Corporation, Winter John M, Long Theodore J, June 11, 1974: US3815747 (8 worldwide citation)

A method and apparatus for softening water in a single conditioning tank system. The water flow through the mineral bed in each service cycle is reversed from the last preceding service cycle and the water-brine solution flow through the mineral bed in each regeneration cycle is reversed from the la ...


2
Clack Willis E, Kay Clifford, Nygren Charles E: Multiple-tank water conditioning system and valve therefor. Clack Corporation, May 11, 1971: US3578167 (6 worldwide citation)

A pair of water conditioning tanks each having a service port. The service ports are connected to each other and to a service outlet conduit. A pair of semibalanced, direct-acting control valves are provided, each having an inlet port, a tank port connected to one of the conditioning tanks, and a dr ...