Clothes washers in a group of three or more have an individual fixture unit rating of __________________________________.

In the context of plumbing codes, fixture unit ratings are assigned to different plumbing fixtures to help determine the overall load they impose on a drainage system. For clothes washers specifically, the Omaha Plumbing Code designates that a single clothes washer in a group of three or more will have a fixture unit rating of 6. This rating reflects the demand on the plumbing system and allows for proper sizing of pipes and drainage systems to accommodate the flow of water and waste generated by multiple washers operating simultaneously.

This rating ensures that when multiple clothes washers are used together, the drainage system is adequately prepared to handle the increased water flow and potential load, preventing backups and ensuring proper function.