Description Amerec Automatic Drain Valve Kit for Amerec AK & 3K Steam Generators. Order One (1) ADK Drain for Each Steam Generator when Ordering Ganged Systems Specifications Automatic Drain Valve Kit for AK & 3K Steam Generators. Automatically Drains Generator for Routine Maintenance Draining after each use. 1/2" Drain Line (Must Drain Lower Than Unit) For use with any Amerec AK or 3K Generator. Amerec steam generators come with a standard manual drain valve which requires regular maintenance a few times a week to drain any sediment and to prevent excessive build-up of minerals from water supply.