Protecting Essential Refining Operations Using Blast-Resistant Electrical Equipment Shelters

This is an introduction to modular steel equipment shelters designed for areas with potential explosion hazards. It serves to review the chronological development of the concept of modular blast resistance, discuss processing industry events driving market demands, and catalog some typical industry responses to date. The paper also reviews levels of industry risk in the context of life safety and protection for essential/critical systems. For the purpose of this discussion, the first tier of risk (personnel protection and life safety) is briefly discussed to provide adequate background. The paper examines the second tier of risk (essential/critical equipment and electrical systems) that facility managers are becoming increasingly concerned with. The paper compares the following: 1) industry guidelines; 2) the known criterion; and 3) the available governing standards for the design and construction of modular blast-resistant structures. It presents a contemporary approach to the second tier of risk and examines the supporting data and analysis. The paper illustrates the process by discussing the following: 1) the design; 2) construction; and 3) testing of one company's blast-resistant modular systems. This includes design verification employing both Single-Degree-of-Freedom (SDOF) models and Finite Element Analysis (FEA). Further validation of the computer modeling techniques was provided by shock tube testing of the structural assemblies, under a range of peak pressures from 5.5 to 60.0 kPa (0.8-8.7 psi). Readers are able to gain knowledge and confidence in the extension of the definition of blast-resistant shelters to include electrical equipment enclosures, further reducing risk and minimizing downtime in the event of an explosive event.