Abstract: The present invention pertains to a liquid fifth wheel assembly for use with tractor and trailer combinations wherein the trailer includes a tank body for the storage and transportation of fluids, and the tractor includes a pumping station adapted to deliver the fluid stored in the tank. The fifth wheel assembly which is secured to the under side of the trailer has a central opening therein through which passes an enclosed dual concentric suction and discharge pipe structure interconnecting the tank and the pump station; the pipe structure including a swivel joint for permitting angular displacement of a portion of the enclosed pipe.