7th Edition International Process Safety Conference (INPSC) 2026, Delhi, India
Vapor Cloud Explosions (VCEs) remain one of the most critical accidental hazards in onshore process facilities, particularly due to their potential to generate damaging overpressures in congested and partially confined environments. The accurate assessment of blast loads on buildings – such as control rooms, substations, operator shelters, and administrative facilities, is essential to prevent structural failure, protect occupants, and avoid either costly overdesign or unacceptable risk.
This presentation provides a comparative evaluation of approaches used to assess overpressure impacts on buildings from VCEs, with emphasis on consequence-based and risk-based methodologies. The governing factors influencing explosion severity – congestion, confinement, fuel reactivity, and flame acceleration mechanisms – are discussed in the context of practical design applications. Typical risk-based acceptance criteria for occupied and support buildings are reviewed, highlighting the need to balance safety, operability, and cost.
Three major VCE prediction methods are examined: the Baker–Strehlow–Tang (BST) model, the TNO Multi-Energy Method (MEM), and Computational Fluid Dynamics (CFD).
The presentation demonstrates how parameter selection – particularly confinement dimensionality, congestion level, reactivity, and curve/strength index selection – significantly influences predicted overpressures for BST and TNO MEM models.
In this presentation, a case study of a compressor shelter handling methane and hydrogen is presented to understand the variability in predicted loads across VCE prediction methods and explosion volumes, emphasizing the sensitivity of results to analyst assumptions.
The role of CFD in highly congested facilities and reactive material scenarios is discussed, including its application for validation and optimization of explosion loads, while recognizing its computational demands.
The study concludes that parameter selection is critical in simplified methods, consequence-based approaches are efficient but potentially conservative, and risk-based frameworks provide more comprehensive design justification. A structured integration of consequence-based, risk-based, and CFD-supported assessments is recommended for robust and defensible building overpressure design.