A rotary union having a housing, a rotor, and a post such that a fluid can be conveyed through the rotary union. The rotor is rotatably coupled to the housing, preferably by at least one bearing interposed between a portion of the rotor exterior and a portion of the housing interior. The post is positioned in the rotary union in a manner effective to help fluidly couple the rotor to the housing and such that an annular gap surrounds at least a portion of the post such that the annular gap constitutes at least a portion of a drain fluid pathway. The present invention also includes fluid delivery systems including such rotary unions and methods of making and/or using such rotary unions.