In this study, the pressing of aircraft fuel system pipes made of Al5052-O into Al7075-T6 flanges has been studied. The hydroforming process uses oil pressure to create large deformations and press the pipe to the flange. The present work was first investigated and designed, then a special tool was made with an innovative method to control the hydroforming pressure application area. In order to check for leaks and observe any mechanical defects, the manufactured parts were subjected to laboratory tests under high pressure. The design was also simulated using the finite element method. In this regard, an attempt was made to make the simulation as close to reality as possible in order to obtain accurate results. The obtained numerical results were compared with the laboratory results that were measurable. In numerical modeling, fuel pipes with different diameters and thicknesses were analyzed and the stress and displacement distributions were obtained. The numerical results show a very good agreement with the experimental results. The simulation results show that the maximum residual stress in the contact area of the pipe and flange is more than 300 MPa, which ensures the sealing of this connection. Also, if the hydroforming pressure is too high, the maximum residual stress in the connection area will decrease slightly. In the present study, the required pressure range is optimally calculated to achieve a desirable residual stress for sealing and connection. In general, this article presents a completely scientific and practical method for creating a permanent sealed connection.