Abstract: A piston device for removing liquids from within a well fluid delivery tube to increase the gas flow therefrom, and for scraping paraffin from the tube walls. The piston has an elongated tubular body formed with a plurality of axially spaced wiper or scraping rings which extend radially outwardly from the body for removing the paraffin from the tube walls. A rotor member is mounted on the bottom of the tubular body and is spaced a predetermined distance below the bottommost ring. A plurality of angled grooves or vanes are formed in the rotor member which causes rotation of the rotor as the piston moves upwardly through the tube. The revolving rotor member produces a turbulence in the space between the rotor and bottom ring which forms a sealing effect across the tube wall providing a greater gas pressure below the piston than above it. The pressure differential causes the piston to rise to the top of the tube bringing with it paraffin and liquid deposits.