The widespread increase in the construction of liquefied natural gas (LNG) processing facilities and gas producing offshore platforms has produced new requirements in designing equipment, in this case pressure vessels, to withstand a blast overpressure condition resulting from the failure of an LNG train or some other form of gas-based explosion. New client requirements are aimed at determining the viability of equipment after one of these catastrophic events. Traditional methods of analyzing pressure vessel response to blast overpressure, such as finite element analysis (FEA) and computational fluid dynamic (CFD) studies, are costly and impractical when applied to large scale projects and tens or hundreds of pieces of equipment. To adequately account for and measure pressure vessel response to blast overpressure, a simplified analytical method is required. However, a simplified method that does not consider the unique conditions presented by an overpressure event produce extremely conservative results (e.g. applying the overpressure as a wind load or pressure times area). Unfortunately, there is limited methodology and literature on blast overpressure phenomena, particularly related to petrochemical refining processes.
This paper will examine the development of a simplified method for analyzing pressure vessel response to blast overpressure using methods originally intended for the study of the effects of nuclear weapons on structures as well as more traditional methodology which employs an explicit solution utilizing modern, commercially available FEA software. The paper will review the methods presented in the existing literature and examine how those methods can be efficiently and practically applied to pressure vessels. The results generated by the simplified methodology will be compared to results from a control case that uses an explicit FEA method to evaluate pressure vessel response to blast overpressure.