Patent ID: 7285210

Claim:
A reverse osmosis water filtering system, comprising: a reverse osmosis membrane having a first output port for permeate water, a second output port for concentrate water, and an intake port for receiving water from a water source; and a flow restrictor for restricting a flow of concentrate water from the membrane to a water source, the flow restrictor comprising: a housing defining an elongated conduit having a tapering conical wall defining a first screw thread and a water-channel thread extending therealong including generally between a first opening into a distal region of the conduit for receiving a flow of liquid and a second opening into a proximal region of the conduit, and an axially elongated plug received into said conduit, with a surface of said plug opposed to said tapering conical wall defining a second screw thread and a smooth tapering surface, said second screw thread disposed in threaded engagement with said first screw thread defined by said tapering conical wall of said housing, and opposed surfaces of said water-channel thread of said housing and said tapering surface of said plug being disposed in sealing engagement within said conduit, said water-channel thread of said housing and said tapering surface of said plug cooperatively defining a generally spiral liquid flow path along said conduit for flow of liquid generally between said first opening and a port defined by said flow restrictor for delivery of liquid from said conduit, wherein said plug comprises first material, said housing comprises second material harder than the first material, and sealing engagement comprises penetrating engagement of said water-channel thread of said housing with said tapering surfaces of said plug.