Abstract: This quick-action flap (1) is provided with a housing body (2), with a service opening (4) let into the housing body (2), with at least two bearing positions (17) for a driven shaft (16), which bearing positions are machined into the housing body (2), and with a flap plate (11) which is fastened on the shaft (16), is pivotable about the center line of the shaft (16) and interacts with a detachable seating ring (10).The intention is to create a quick-action flap which can be manufactured easily and which is secured particularly well against long-term jamming at comparatively high operating temperatures and pressure loads. This is achieved by the bearing positions (17) being arranged outside the service opening (4) region which causes inhomogeneous stress distributions in the housing body (2).