Abstract: A fluid distributor for use in ion exchange vessel assemblies contain ion exchange resins, particularly fixed-bed assemblies. The distributor includes a hub containing a central fluid passage and at least two sets of laterally disposed, fluid-distributing conduits. One of the sets of lateral conduits has holes screened by a fine, resin-retaining mesh. A remotely-controllable valve assembly disposed in the hub regulates flow between the hub and the sets of lateral conduits, so that flow between the screened conduits and the hub may be shut off. The hub also includes means for adjusting the relative rate of fluid flow through the sets of lateral conduits.