To determine the internal static overpressure generated by the catastrophic failure of a liquid Nitrogen (LN2) dewar, we look at the physics of a Boiling Liquid Expanding Vapor Explosion (BLEVE) and the resulting rapid phase transition.
So I asked Google Gemni + to calculate the pressure wave in a room that is 40′ X 40′ X 20′ tall with the catastrophic failure of a 1-ton chlorine cylinder. In a 32,000 ft3 room, we must determine the volume of gas released during the “instantaneous flash” and the resulting internal static overpressure.
DISCLAIMER: This is a “cheat sheet” for safety professionals to get a general idea of the “safe distances.” ALWAYS refer to ASME PCC-2, Mandatory Appendix 501-III) for the exact distance. Just understand, ALL pneumatic pressure testing REQUIRES a “safe distance”. According to ASME PCC-2, Mandatory Appendix 501-III, determining safe distances for pressure testing—specifically, pneumatic testing—requires
So I asked Google Gemni + to calculate the pressure wave in a room that is 40′ X 40′ X 20′ tall with a 5,000-gallon pressure vessel 85% full of liquid NH3, and it catastrophically fails. How much of a pressure wave will this event create in psig? I promise you this… No Engine Room
The risk management program in 40 CFR Part 68 requires facilities to conduct an off-site consequence analysis (OCA) to provide information to state, local, and federal governments and the public about the potential consequences of an accidental chemical release. When does a facility need to revise its OCA?
For the purpose of analyzing the worst-case release scenario required as part of the hazard assessment at 40 CFR Part 68, Subpart B, the worst-case release quantity is identified as the greatest amount held in a single vessel or pipe, taking into account administrative controls that limit the maximum quantity (40 CFR §68.25(b)). Are mechanical
Pursuant to the risk management program regulations, facilities must perform an offsite consequence analysis for the worst-case release scenario. Do the quantities of two (2) separate vessels that are interconnected with a closed valve need to be aggregated for the worst-case release scenario analysis?
In section 2, element 2.5, of an RMP, facilities must report the quantity of toxic chemical that the facility used for the worst-case analysis. When reporting this data element in RMP*eSubmit for a mixture, should facilities report the entire weight of the toxic mixture potentially being released or only the amount of the regulated toxic
Pursuant to the Risk Management Program regulations, the owner or operator shall identify and analyze at least one (1) alternative release scenario for each regulated toxic substance held in a Program 2 or Program 3 process above its threshold (40 CFR §68.28). If a facility has both ammonia and ammonia (anhydrous) on site above their
Tentative Interim Amendment (TIA) 27-1 refers to a significant update to the 2027 Edition of NFPA 30: Flammable and Combustible Liquids Code. Issued on April 15, 2026, with an effective date of May 5, 2026, this TIA (Log #1886) was processed by the Technical Committee on Flammable and Combustible Liquids to address safety gaps regarding
Under Cal/OSHA’s Process Safety Management (PSM) standards (specifically Title 8 §5189.1 for refineries and §5110.16 for other facilities), the Hierarchy of Hazard Control Analysis (HCA) is a formal, documented requirement that goes significantly beyond the traditional OSHA “inverted pyramid.” While standard safety protocols often treat the hierarchy as a suggestion, Cal/OSHA makes it a mandatory
