—Developed initially on the basis of electronic technology, the researches in the field of reliability have proved their generality, so they can be applied to any technical system including the welding by pressure equipments. The structure of the welding by pressure equipments and their specific characteristics result in a more difficult reliability assurance of this type of systems. In this paper, the reliability assurance of the welding by pressure equipment was achieved by reliability modeling and renewal policies. A case study demonstrates the application of the approach.