Support tube for a filter element

A filter element comprising:

• a support grid structure having center axis, the support grid structure radially circumferentially surrounding and defining an open cylindrical interior, the support grid structure having a first axial end and an opposing second axial end on said center axis;
• a filter medium arranged on the support grid structure, the filter medium radially surrounding and circumferentially closing around the support grid structure;
• the support grid structure comprising elongated structural web members that are directly connected with other ones of the elongated structural web members and form a hollow-cylindrical grid structure that surrounds the cylindrical interior;
• wherein the structural webs are arranged such that at least three of the structural web members or structural web sections of the structural web members that are directly connected to each other define a through opening, respectively, wherein a fluid flow is enabled in a radial direction relative to the center axis of the hollow-cylindrical grid structure through the through openings;
• wherein a first average opening cross-section of the through openings in a first region adjacent to a first axial end is greater than a second average opening cross-section of the through openings in a second region adjacent to the second axial end;
• wherein some of the structural web members are slanted structural webs slanted relative to the center axis;
• wherein slanted structural webs are not aligned parallel to and not aligned perpendicular to the center axis;
• wherein said slanted structural web members are positioned in the first region at a first slant angle slanted relative to a normal plane to the center axis and are positioned in the second region at a second slant angle relative to said normal plane;
• wherein the first slant angle is greater in magnitude than the second slant angle;
• wherein the first slant angle changes stepwise into the second slant angle in an axial direction of the support grid structure.