52 into the vessel 12 the regenerated purified and rinsed cation material is transferred from the vessel 12 to vessel 10 through conduit 80 by introducing a transfer flow of water into vessel 12 through pipes 20 and 30 and opening valves 82 and 84 the regenerated purified and rinsed anion material is transferred from the storage vessel not shown by introducing a transfer flow of water into the storage vessel and transferring the anion material through conduit 86 and opening valve 88 and appropriate valves on the storage vessel interconnecting pipework when the regenerated purified and rinsed anion and cation materials have been transferred to vessel 10 they are remixed they can be held in vessel 10 until required for service or moved to the storage vessel not shown in either case they will be rinsed to a very low conductivity before being placed in service in either event when vessel 10 is finally emptied the mixture of materials held in the isolation vessel 64 is transferred to vessel 10 to await the next batch of materials for regeneration the transfer is accomplished by a flow of water from 26 by closure of the valves 58 and 98 and the opening of the valves 56 68 and 96 if necessary following the transfer the.