Patent ID: 8128816
Filing Date: 2012-03-06
Classification: B01D,G01F,G01N,Y10T

Abstract:
1. In a preparative chromatogaphy column comprising a cylindrical tube and a piston head retained within said tube and movable therein along a longitudinal axis, said piston head having an upper surface and a lower surface, the improvement comprising: an aperture in said piston head having an axis parallel to said longitudinal axis; a removable plug insertable into said aperture from said upper side of said piston head to seal said aperture against fluid entry; and a rod insertable through said aperture from said upper side of said piston head when said removable plug is removed therefrom, said rod being sufficiently long to protrude below said piston head to a variable length and bearing indicia to indicate the length of said rod protruding below said piston head.