Check valve with integrated pressure relief valve

A check valve (1), comprising:

• a valve body (3) which by incoming water in a flow direction (Pf1) is movable counter to a restoring force, from a closed position in which the valve body (3) bears on a first valve seat (4), to an open position in which the valve body (3) is raised from the first valve seat (4);
• a pressure relief valve (5) which has a closing member (6) which by a pressure of the water returning counter to the flow direction (Pf1) is movable counter to a restoring force, from a closed position in which the closing member (6) bears tightly on a second valve seat (7), to an open position in which the closing member (6) is raised from the second valve seat (7);
• wherein the restoring force acting on the closing member (6) of the pressure relief valve (5) is greater in comparison to the restoring force acting on the valve body (3);
• and wherein
• the closing member (6) of the pressure relief valve (5) has a closing member core (8) from a first material, said closing member core (8), at least in a sub-region of the closing member core (8) that in the closed position bears on the second valve seat (7), carries a film or a layer (9) from a second, at least one of comparatively softer material than the closing member core or an elastic material, and the film or layer (9) has a thickness that is 0.50 mm or less and extends with the thickness on the closing member (6) in an extent direction of the second valve seat (7) in the flow direction,
• wherein a first circumferential sub-region of the closing member core (8) on an inflow side of the of the closing member core (8) that contacts the second valve seat (7) in the closed position is a ball segment or a spherical segment,
• wherein a second circumferential sub-region of the closing member core (8) on an outflow side of the closing member core (8) is a cylindrical segment,
• wherein the closing member (6) is a bi-component or multi-component injection-molded plastic part comprising the closing member core (8), an inflow-side stopper (13), and an outflow-side stopper (14),
• wherein the inflow-side stopper (13) has a cylindrical stopper shape and is disposed on the inflow side on the closing member (6) and is oriented in the flow direction (Pf1), and
• wherein the outflow-side stopper (14) is disposed on an outflow side of the closing member (6) and is oriented counter to the flow direction (Pf1).