Wick material is included along the length of the interior and exterior walls of vapor recovery and product hoses, respectively, the product hose being carried within the length of the vapor recovery hose, whereby the wick material absorbs liquid entrapped between the hoses, and substantially increases...http://www.google.com.tw/patents/US4570686?utm_source=gb-gplus-share專利 US4570686 - Apparatus for preventing blockage of vapor recovery hose by liquid fuel
