Projeto e metodologia de análise da perda de propriedades mecânicas de parafusos em equipamentos estáticos

Abstract

Expenses with maintenance represent a large share of costs associated to operation in the industrial field. Therefore, it becomes relevant to adopt strategies which seek to minimize this type of expense, acting towards the sources of expenses with materials, labor and services. This project has the goal of reducing the maintenance costs related to material replacement every scheduled maintenance in Braskem S.A. at Camaçari. Nowadays, at each stoppage, every bolt of flanged joints is switched, according to the enterprise's internal procedure. It is believed that, despite the procedure’s imposition, there is no practical limitation to reusing the bolts in more operation cycles. Thus, the project has the intention to develop a methodology of tests and simulation of operation which allows the team to evaluate the decay of bolts properties after each cycle, then verifying if the bolt is still good enough to be used again. For that to happen, a few specifications were restricted, such as the bolt’s diameter, the piping’s pressure class, and the equipment’s temperature of work. These restrictions were imposed as a way of reducing the project’s scope, although it still embraces a fair share of statical equipments within the industrial plant. In order to simulate the operation, the bolts will be submited to a calculated torque which simulates the effects of preload, piping pressure and external tensions. Then, the bolts will be submited to a series of 6 tests to verify their properties, and later evaluate the possibility of reuse. The detailed project explores the practical aspects of the project, after the theoretical basis generated in the informational project. Therefore, this document presents the definitions and decisions which were made, based off the informational project, as well as the results defined to the project, and the methodology for analyzing the bolts in itself.