AMI Flow Restrictors are designed for use in residential reverse osmosis systems to restrict the flow on the drain (reject) line, keeping the membrane pressurized and controlling the recovery ratio of the system. The flow restrictor must be properly sized according to the flow of the RO membrane system. It is recommended that the flow restrictor is replaced each time an RO membrane is replaced in order to keep your system working at optimum performance, as scale build-up can occur and clog the capillaries. Additionally, if changing to a different flow-rate membrane element, the flow restrictor must be changed to the appropriate size as well.