Devices and methods for preparing a transcatheter heart valve system. The device includes a housing, sealing apparatuses and a port. The housing forms a chamber sized to receive a prosthetic valve and a portion of a delivery device. During use, the prosthesis is seated in the chamber, and the sealing apparatuses operated to seal the chamber about the delivery device. Air bubbles in a liquid delivered through the delivery device and to the chamber are removed from the system via the port, thereby flushing the system. Further, the device is manipulated to permit loading of the prosthesis into the delivery device in an air bubble-free environment.