Nnmechanical seal failure analysis pdf

All these studies have basically regarded the traditional bolted flange joints. As per the seal vendor spec, the max pressure limit for bellows is 15 bar, which. The rubber drive ring was forced up into the seal the seal came apart upon final installation. Analysis of a mechanical seal failure in maintenance organizations where time and cost of repair are crucial elements, it is of paramount importance for a reliability engineer to determine swiftly and accurately the failure modes and root causes underlying a particular issue to avoid further machinery breakdowns. The shaft seal is exposed to widely varying operating conditions. The appearance of the seal can provide significant insight into potential causes of. The wrong lubrication was used as indicated by the transfer of carbon to the mating ring. Failure analysis is not always straightforward and exact, but it does follow a systematic approach, so it. Pdf on jan 1, 2012, jasbir singh and others published failure mode analysis of mechanical seals find, read and cite all the research you need on researchgate. Vpacking female adapter ring showing clear signs of extrusion. All other losses simply classed as non mechanical integrity failure secondly, all mechanical integrity failure losses then classified.

The failure mode of mechanical seals and the various cause events to help in taking appropriate steps to improve sealing reliability are discussed by singh et al. In sealing structures, failure of the rubber oring seal may lead to catastrophic. Case studies in engineering failure analysis journal. An analysis of common causes of major losses in the. This article presents a study on failure analysis of mechanical face seals using reliability tools such as the weibull and weibayes techniques. Parameters changed after introduction of plan 32 were. Introduction to failures failure of the mechanical shaft seal is the most common cause of pump downtime. The analysis of an oring or seal failure includes many factors, including the environment, the seal design and the elastomer itself. It is to be noted that same seal never displayed this type of failure mode prior to introduction of high pressure external seal flush. Sometimes operating conditions change to become quite different from the specific conditions for which the seal was intended. The weibull distribution is used to fit the failure data of mechanical seal and build. Sealing failure analysis on vshaped sealing rings of an. Failure modes of a mechanical seal can be identified by three main causes of failure.

Analysis of a mechanical seal failure reliabilityweb. The first step in a seal failure analysis is to determine what, exactly, constitutes a failure. Mechanism based failure analysis university of twente research. In addition, these same techniques will be applied to monitoring opportunities for mechanical seal piping plans in operations. Damage to the seal from the gap between the sliding surface and housing.

The weibull tool is used when a reasonable number of failure data are available, whereas the weibayes approach is employed when the failure data are scarce or nonexistent. Detailed information is required to make a failure analysis of a damaged shaft seal and subsequently prevent new failures. Failure of mechanical shaft seals the knowledge link. This section describes the most common failure modes seen. This course will introduce root cause analysis rca, function evaluation, and mechanism identification in the context of mechanical seal failure investigations. After this general analysis, the four identified critical failure modes are analyzed in more detail and the failure mechanisms are determined. Influence of randomness in rubber materials parameters. Failure analysis and troubleshooting mechanical seals and. Any company buying mechanical seals from a reliable vendor has the right to expect a sensible failure analysis on the majority of their seal failures. Click here for full pdf version of this article includes all graphs, charts, tables and author information. This seal operated in a very dirty environment and the mating ring bore does not appear to be concentric with the shaft.