High and Low Frequency Vibrations in Flare, Piping Systems: Causes, Consequences, and Avoidance Screening Methodology

Abstract

Abstract Designing a new flare system or evaluating the integrity of an existing one has become a more complicated practice in the last few years. The original design of the flare system was probably based on a simple static analysis and code compliance, and didn’t consider the different types of vibration sources that will affect the integrity of the flare system in the short or the long term, these was not obvious to the designer, especially as most piping design codes don’t address vibration in a meaningful way. Recently, incidents have occurred world wide where piping failure was related to unexpected piping vibration, this typically occurred due to increased fluid flow as a result of de-bottlenecking and the relaxation of erosion velocity limits. There also was a tendency by designers to use thin walled pipe for economic reasons and to allow increased flexibility in the piping system. This is very common on lower pressure designed relief and flare systems. This paper will consolidate the guideline, techniques, definitions and equations related to High and Low Frequency Vibrations in Flare Piping System to get better understanding of the nature of these vibrations, I will also describe how to build a screening tool and provide examples from two Egyptian gas plants to see practically how the screening assessment was completed.