forming a form fitting connection through which the liquid filter is detachably and sealingly connectable to a counterpart the counterpart may be a flange connected directly to a machine assembly or it may be an adapter element for adapting the form fitting connection to connect to a conventional threaded connector application_number US 29561905 A description fig1 shows a liquid filter 10 which comprises a filter medium 12 in a filter housing 11 the filter medium 12 is mounted in a sealed manner between an upper end disk 13 and a lower molded disk 17 the upper end disk 13 may be made for example of an elastic nitrile rubber and the lower molded disk 17 may be made for example of a thermoplastic synthetic resin such as polyamide or polypropylene the interior of the hollow cylindrical filter medium 12 is supported against a central tube 14 through which the flow can pass support tube 14 is manufactured in one piece with a tube collar 14 a arranged on the upper end face the filter medium 12 is supported through the tube collar 14 a relative to the housing 11 by a metal spring plate 15 the filter medium 12 is centered and secured axially in the housing 11 by metal spring plate 15 furthermore a bypass valve 16 is attached to the metal spring plate 15 and.