The CPL technology has been under development for the last 15 years. Many technical and manufacturing issues have been worked out. However the deprimes of capillary pumps have remained the most difficult problem to solve. The Advanced CPL (A-CPL) design concept was proposed in an effort to make the capillary pumps more tolerant to both vapor and noncondensible gases. A test loop was constructed to demonstrate the operational principles of the A-CPL at room temperature. Freon 134a was chosen as the working fluid so that Teflon tubing could be used as the loop transport lines for flow visualization purposes.