Abstract: A packing for a vessel to contact fluid therein wherein the packing comprises a plurality of insert units, each insert unit comprising a plurality of transversely extending elements disposed longitudinally along the insert unit and angularly thereabout wherein a portion of each transverse element lies in close proximity to a first individual conceptual surface characterized in that the insert units are disposed in side-by-side relationship in a regular manner and the cross-sectional area between adjacent individual conceptual surfaces of adjacent insert units at least at one position longitudinally of the plurality of insert units is no greater than the maximum cross-sectional area within an individual conceptual surface of an insert unit between two adjacent transversely extending elements thereof at any cross-section longitudinally of the plurality of units.

Abstract: A method of making an insert comprising an elongate core having a plurality of loops disposed longitudinally therealong and angularly thereabout by taking such an insert wherein a portion of each loop lies in close proximity to a first conceptual enveloping surface and deforming the loops or displacing the loops so as to be inclined to the longitudinal axis of the core so that a greater proportion of each loop periphery is in close proximity to a second conceptual surface of smaller cross-section than said first surface. Also disclosed are inserts made in the above way and vessels incorporating such inserts.