Extension part, injection valve and fuel delivery assembly

An extension part (5) for an injection valve (1) for a combustion engine, the injection valve (1) comprising a base injector part (3), is specified. The extension part (5) comprises a first fluid inlet portion (7) with a first sealing section (9) and a fluid outlet portion (11). The first fluid inlet portion (7) of the extension part (5) is designed to be coupled to a fuel rail cup (13) in such a way that the first sealing section (9) of the first fluid inlet portion (7) is coupled in a given first coupling area (15) in a force-fitting manner with the fuel rail cup (13). The fluid outlet portion (11) of the extension part (5) being designed to be coupled to a second fluid inlet portion (17) of the base injector part (3) in a given second coupling area (21) in a force-fitting manner. Further, an injection valve (1) and a fuel delivery assembly are specified.