Piping systems constitute the most critical portion of process plants. Proper blast and fire design of piping systems improve safety and resiliency. Design of piping and pipe supports are typically governed by operating and abnormal conditions depending on the design basis. Well established analysis and design methodologies as per the applicable ASME codes ensure performance of piping systems against loads such as internal pressure, thermal expansion, self-weight, wind, seismic and vibration cases. Pipe stress analysis using empirical and linear elastic analysis methods allow design for these types of conventional load cases in a practical way. However, beyond design basis load cases due to hydrocarbon accidents including explosion and fires can pose challenges. This is Limitations of conventional design tools against demands due to extreme events require use of more advanced techniques. This study presents a practical approach for assessment and design of piping systems for hydrocarbon accident events.Major accident events are rare. It is typical to consider a return period of 1,000 to 10,000 years for determination of accident scenarios. Given the low probability of these events, it is not recommended to use conventional design criteria and standard analysis tools since it will be conservative. Strain-based approach to predict failure is a more suitable and refined method for extreme loads. Non-linear finite element analysis of piping systems has been successfully implemented for offshore and onshore projects for life safety and asset protection. Consideration of system behavior accounting for interaction of piping and support structures is another key element of the design approach discussed in this study. This comprehensive assessment approach also includes strain rate dependency and temperature degradation for blast and fire cases, respectively.Examples from major projects and case studies are presented to demonstrate the technical approach. Piping systems designed for conventional approach were analyzed for fire and blast cases using ABAQUS software. Explicit dynamic analyses and transient analysis were performed to qualify the piping systems for blast and fire cases, respectively. It is shown that blast response of the piping systems and support structures including pipe racks and process modules can be improved with some minor upgrades in case of failure risks. For most cases, the piping systems were qualified against blast loads without any changes through refined analyses. Assessments against pool and jet fires included evaluation of piping systems and supports with and without Passive Fire Protection (PFP). It is shown that PFP requirements can be significantly optimized for piping, equipment, pressure vessels and support structures.This study provides generic guidelines on practical design and optimization of piping systems subject to accidental fire and blast loads. Best practices and design recommendations are provided based on applications from a range of Oil&amp;Gas projects globally. Mitigation measures such as additions of hold-downs, guides and strengthening of pipe supports can be required for rare events with high blast overpressures if the piping system is not qualified through analysis. Passive fire protection design can be optimized through a combination of risk calculations and ductility level fire integrity analysis.

Design of Piping Systems for Accidental Explosion and Fire Events

Paper Proceedings: https://asmedigitalcollection.asme.org/PVP/PVP2021/volume/85314

ASME 2021 Pressure Vessels & Piping Conference (PVP2021)

Supporting the need among researchers worldwide for additional online and multimedia content, ASME now offers the ASME Conference Video Collection. This platform will collect and provide long-term access to conference presentation videos, encompassing all technology areas within ASME's technical conference and events program. About 30,000-40,000 engineers across all mechanical engineering and related disciplines participate in ASME conferences each year. This includes authors of approximately 6,000 to 8,000 technical papers published by ASME, the majority of whom also submit video presentations for our virtual conferences. The video collection will be available as an add-on to existing product packages or as a separate subscription.