The International Journal Of Engineering And Science (IJES) || Volume || 5 || Issue || 4 || Pages || PP -90-96|| 2016 || ISSN (e): 2319 – 1813 ISSN (p): 2319 – 1805 www.theijes.com The IJES Page 90 Failure Analysis of Feedstock Preheater Unit of the Kaduna Refinery using Failure Modes Effects and Criticality Analysis (FMECA) Ibrahim Z. Z 1 .Ibrahim A 2 .and El-Nafaty U. A 2 1 Department of Petroleum Engineering, Abubakar Tafawa Balewa University, Bauchi State, Nigeria. 2 Department of Chemical Engineering, Abubakar Tafawa Balewa University, Bauchi State, Nigeria. ---------------------------------------------------------- ABSTRACT------------------------------------------------------------ The use of failure modes effects and criticality analysis (FMECA) as a failure or reliability analysis tool, checks the probabilities that an item will perform a required function under stated condition(s) when operated properly.Failure analysis of process equipment is an important issue in any process industry. This study aims at analyzing the failure of feedstock preheater unit of the Kaduna Refining and Petrochemicals (KRPC), Fluid Catalytic Cracking Unit (FCCU), using the failure mode, effects and criticality analysis (FMECA). The unit failure and its effects were identified through seven sub-units (fresh feed surge drum, heavy naphtha exchanger, light cycle oil exchanger, heavy cycle oil exchanger, fractionator bottom exchanger, feed preheater and fresh feed charge pump), using the failure mode effects analysis (FMEA). Both quantitative and qualitative criticality analyses (CA) were used for failure analysis of the unit (feedstock preheater). For the qualitative analysis, items risk priority number (RPN) were computed and it was found that, four sub-units (heavy naphtha exchanger, main fractionator bottom exchanger, feedstock preheater, and fresh feed charge pump) had their Risk Priority Number (RPN) greater than 200, these sub-units are said to be critical. Three of the sub-units (fresh feed surge drum, light cycle oil exchanger, and heavy cycle oil exchanger) had their RPN less than 200, these sub-units are said to be less critical. For the quantitative analysis, items criticality number (Cr) were computed and it was found that most of the sub-units had their Cr>0.002. In addition, the results of the criticality matrix showed that, eight out of the sixteen failure modes identified were above or closely below the criticality line. Finally, FMECA was effectively used for failure analysis of the feedstock preheater andpredictive maintenance was recommended. Keywords: FCCU, Feedstock Preheater, Failure Analysis, FMEA/FMECA, Risk Priority Number, Criticality Number, and Criticality Matrix. ---------------------------------------------------------------------------------------------------------------------------------------- Date of Submission: 26 March 2016 Date of Accepted: 29 April 2016 ---------------------------------------------------------------------------------------------------------------------------------------- I. INTRODUCTION The feedstock preheater is a train of heat exchangers used to preheat the fresh feed normally the heavy gas oil (HGO) and vacuum gas oil (VGO) at a temperature range of 300 – 330 o C. Heat from the product which is to be cooled, is recovered by the feedstock preheaters. The feed heat is further increased by the feed furnace and then introduced into the base of the riser (Chiyoda [1] , 1980 and Hendrix [2] , 2011). The failure of this unit is of great concern, because it may lead to complete shutdown of the FCCU. Therefore, the failure analysis of this unit (feedstock preheater) using the FMECA cannot be over emphasized. FMECA was one of the first systematic techniques for failure analysis.It is a technique used to identify, prioritize, and eliminate potential failures from the system, design or process (Rausand [3] , 2005). FMECA methodologies were designed to identify potential failure modes for a product or process before the problems occur, to assess the risk (Sultan [4] , 2011 and Maley [5] , 2012). This tool was used byThangamani, et al [6] , 1995 to assess the reliability of a FCCU, and from their results, the reliability was found to be low.Masoud, etal [7] , 2011 applied this tool for failure analysis ofan oil industry in Iran. Also, Flecher [8] , 2012 used this tool to assess the risk of Sinopec X’ian branch FCCU. His result showed that reactor-regenerator systems have the highest potential hazard. In addition, Mahendra [9] , 2012 applied FMECA for ensuring reliability of process equipment. At the end of his work, highly critical systems and failure modes were identified and that the duration for which the equipment is out of work is reduced significantly. Ibrahim, et al [10] , 2015 used the tool for the reliability of a reactor – regenerator unit. Similarly, Ibrahim, et al [11] , 2016 used the tool to assess the reliability of fractionation column. Their results showed that the reliabilities of the units were found to be low.