Filter system with non-return valve and filter element

A filter system for filtering a fluid, the filter system comprising:

• a filter housing comprising a housing top part and further comprising a housing bottom part, wherein the housing top part and the housing bottom part extend along a housing axis;
• an outlet socket arranged at the housing top part and configured to discharge the fluid after having been filtered;
• a non-return valve having a valve housing mounted and affixed onto a n interior surface of the outlet socket of the housing top part;
• wherein the non-return valve comprises:
• a closure element;
• a spring element supported at the top housing part and acting against the closure element to urge the closure element into a closed position on a valve seat;
• an annular valve holder arranged in the interior of the outlet socket of the housing top part and mounting the valve housing onto an interior surface of the outlet socket of the housing top part, the annular valve holder comprising:
• at least one radially inward projecting web against which the closure element of the non-return valve rests when the filter element is removed from the filter housing;
• a filter element arranged in the filter housing and separating a raw fluid side and a clean fluid side from each other, wherein the filter element comprises:
• a filter bellows arranged about a longitudinal axis of the filter element;
• an end disc arranged on an end face of the filter bellows, the end disc having a central opening configured to drain the fluid after having been filtered from an interior of the filter bellows,
• the filter element further comprises a central tube arranged in the interior of the filter bellows, wherein the central tube comprises the socket of the filter element forming the valve seat at an end of the central tube facing the end disc,
• a socket of the filter element arranged in the filter element and extends in an axial direction along the longitudinal axis of the filter element to open axially outwardly through an interior of the central opening of the end disc;
• wherein the socket of the filter element forms the valve seat of the non-return valve;
• wherein the socket of the filter element projects through the annular valve holder to contact and lift the closure element off of the at least one radially inward projecting web of the annular valve holder when the filter element is arranged in the filter housing;
• wherein the non-return valve closes a fluid path through the outlet socket when in the closed position, and opens the fluid path through the outlet socket when the non-return valve is in an open position.