Aumento de confiabilidade de válvulas guilhotina de um sistema de despoeiramento

Abstract

Knife valves are widely used in Environmental Control Equipment. Their lack of reliability brings increased maintenance costs and the possibility of operational impacts. Improvement actions through the application of hard, and more expensive, material on the faces that under wear were under study. The application of Reliability Engineering allowed to identify the reasons for failures along the life of the valves, and consequently, the necessary maintenance actions to increase reliability. A fundamental step is the team leveling of the types of failures and the standardization of the servicing returns of these valves. Generating thus a history with quality that allows a LDA (Life Data Analysis) the most probable with regard to life until failure of the components. The RDB (Reliability Block Diagram) with a simple series configuration demonstrates the contribution that each component has to the decrease of the reliability of the valve, in the respective life time. This greater clarity about how each component of the valve fails allows prioritizing maintenance actions more efficiently. Proving that the application of harder material would not increase the reliability of the valves in the initial life time, being its positive contribution only after 647 days in operation. And that the use of the original spare parts added to a revision of the criteria in the maintenance would increase the reliability of the valve effectively, without adding the costs coming from the application of the hard material.