A fuel injector for a turbomachine, the injector comprising from upstream to downstream a sealing valve, a diaphragm and a metering device, the fuel injector comprising from upstream to downstream an inlet body, a central body into which the inlet body opens, a fixing plate for fixing the injector to a combustion chamber wall, an injection unit and an injector nose, the injector being delimited to the exterior of the injector by a casing (13, 30), the inlet body accommodating the sealing valve inside the casing, the valve comprising a stopper, a spring and an inlet nozzle, the spring biasing the stopper in a closed position, the inlet nozzle being configured to act as a seat for the stopper, the stopper comprising a body, an inner pipe inside the body and admission pipes which open into the inner pipe through the body, the body of the stopper comprising an annular wall, a base wall and an annular contact edge, the base wall closing the stopper upstream and the contact edge being designed to come into contact with a gasket in a closed position of the stopper, each admission pipe being a channel extending between an intermediate space and the inner pipe, the admission pipes being angularly distributed through the body of the stopper and being inclined downstream relative to the longitudinal direction of the inlet body, the intermediate space being radially delimited to the exterior by an internal surface of the casing and being radially delimited to the inside by the stopper in a closed position of the stopper, the intermediate space connecting the inlet nozzle to the stopper in an open position of the stopper and being devoid of any fluid communication with the inlet nozzle in a closed position of the stopper, the inlet nozzle comprising an annular body which is traversed at its two opposite ends along the longitudinal direction of the inlet body by an inlet and an outlet, the inlet nozzle being traversed by a central pipe which extends from its inlet to its outlet, the inlet opening to the exterior of the injector, the annular body comprising an annular rim surrounding the central pipe and comprising a housing for a gasket, the housing being delimited by a base wall, an opening opposite to the base wall, and two opposite walls (65, 67) which each extend between the base wall and the opening, the gasket being in contact with the stopper in a closed position of the stopper by preventing the fuel from flowing between the outlet of the inlet nozzle and the inner pipe, characterised in that the gasket is crimped into the housing by the walls (65, 67) which are inclined towards one another in the direction of the opening, the walls (65, 67) are spaced apart by a distance (d) which is equal to at most 70% of the maximum diameter of the gasket along a radial direction in the longitudinal cross-section of the inlet body, to close the housing, the annular rim comprising an evacuation pipe opening into the housing and to the exterior of the inlet nozzle, the evacuation pipe being configured to evacuate fluid out of the housing, at least one part of the evacuation pipe extending along a direction (Z 2 -Z 2) which is substantially parallel to the longitudinal direction (X-X) of the injector body, and being formed by a groove provided on a radially external surface of the inlet nozzle facing the internal surface of the casing.