Maintenance has not else been seen just as an expenses generator by worldwide companies. According to the importance it has taken on, new investments in technologies and tools were implemented. In companies, it increased the need of costs reduction, equipment and installation availability and reliability, and at this point, maintenance has stood out, each day more, as a fundamental area for success of those companies who have strong and large industrial bases. However, maintenance had a big technological improvement, mainly in predictive maintenance concepts, subject which always work in order to the development of new technologies and methodologies, and also new techniques for equipment integrity evaluation, on operational conditions. Therefore, in this Dissertation, tests were carried out in several specimen (ASTM A 516 / A 516 M - Grade 60 Steel), using tension test as loading conditions, to stimulate the specimen structurally, and consequently, the generation of acoustics emission signals. The specimen were monitored through acoustics emission tests, in each loading steps previously established, for their structural integrity evaluation. Than, the results were digitalized, stored and processed in the Acoustics Emission Equipment, for further analysis. All the results are presented as a graph, and also were studied, analyzed and compared. We can conclude that it is possible to use the acoustics emission test for structural integrity evaluation in equipment under working conditions, and it is capable to realize, detect and locate active sources, that can be compromising to the equipment structural integrity, and also capable of make possible an maintenance team intervention, without causing premature failures which provoke breakdowns.