Provided is an electrically conductive elastic composite yarn having an elastic member that is surrounded by at least one conductive covering filament. The prosthetic valve comprises an anchoring member, at least one leaflet, and a restraining member capable of temporarily preventing substantial movement of the leaflet between and open and closed position so as to allow fluid flow in the antegrade and retrograde directions. The process typically makes it possible to hydrorefine an olefinic gasoline by more or less eliminating the diolefins and sulphur compounds. The outer housing also includes an end cap having a contoured wall an engagement portion, a chamber, and an open end.