This thesis investigates potential materials to be used in the rotary sealing industry that provide low power loss and minimize cost. The studied rotary valve utilizes slots that act as timing valves to allow for flow axially, through the seal face, at particular times within a heat pump cycle. This investigation examines various combinations of multiple PTFE materials, plastics, and soft metals that have been proven to provide low friction coefficients. Leakage and wear requirements are stated for the future use of the rotary valve and are used to determine the effectiveness of sealing the fluid while examining the power loss. In conclusion, the study finds the combination of a modified PTFE stationary ring and Aluminum Bronze rotating face to provide the lowest power loss. Numerical analysis was completed to verify the lubrication regime to be partial lubrication and was also used to investigate geometry changes and impact on the power loss.