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.