Análise de confiabilidade das válvulas de ar quente de um alto forno

Abstract

This work consists in analyse the behaviour of NPS 60” Hot Blast Valves (HBVs) for Blast Furnaces Stoves in ArcelorMittal Tubarao (AMT). Those valves are very critical equipment with a high purchasing cost. Their failures have a high loss potential. The valves performance, as well as their failures history, can be precisely tracked at the company Computerized Maintenance Management System – Sismana. Reliability curves for the valves can be defined using the referred data. There are four HBVs in operation at Tubarao Blast Furnace 01. The proposal is to define a period of time for data sampling, noting the equipment non-operating periods. The intention is to stratify the information for a reliability assessment. In parallel, it will be used a Reliability-Centered Maintenance approach (RCM), aiming to raise the reliability performance of the systems analysed, in addition to result in greater maintenance budget assertiveness. The analysis will be conducted at AMT Blast Furnaces Production Management facilities, using the maintenance registers stored in Sismana. According to the equipment characteristics it is not possible to expect concrete results of reliability improvements during the execution of this work. Such improvements depend on at least 02 years for validity verification, considering the current lifetime history of valves to be studied. However, the actions defined in the RCM study can be implemented immediately to improve the analyzed equipment results, which subsequently can be measured and compared to the current ones. Considering the high costs associated with the valves acquisition and refurbishment, their high potential of losses in case of failures, and the existence of ten units in AMT Blast Furnaces continuous operation, it is clear that those equipment reliability improvement will bring relevant impact to the plant operational results.