A system for remotely venting an expansion bladder employed in a liquid-filled container, such as an outer housing of an x-ray tube. The remote venting configuration provides the expansion bladder with access to atmospheric pressure existing about the x-ray tube so as to enable it to compensate for pressure changes within the liquid-filled container that occur as a result of liquid heating. Further, the remote nature of the bladder venting system enables the expansion bladder to be positioned within a portion of the outer housing that is radiation shielded, while the remote venting portion of the system is positioned in an unshielded portion of the housing. This eliminates the need to perforate the radiation shielding of the outer housing in order to provide atmospheric pressure to the bladder. Further, the remote vent is semi-permeable so as to prevent liquid escape from the system in the event of bladder rupture.