A adapted filter assembly for insertion into the interior chamber of the pressure vessel, wound concentrically around a central permeate tube extending along an axis (X) to form the inlet spiral surface and an outlet volute surface and, at least one membrane envelope and feed spacer sheet, and a cylindrical outer peripheral surface of the includes a spiral membrane module, and brine seals disposed concentrically around a portion of the outer peripheral surface, a, i ) is adapted to engage the interior chamber of the pressure vessel to define a maximum outer diameter, coated with a flexible lip extending radially, ii) a portion of the first spiral surface, and the rear cap surface, for iii) allowing fluid to flow through the inlet spiral surface to the module feed spacer sheet, at least one opening in the rear end cap surface Characterized brine seal comprising a part, the filter assembly. .Field