Overpressure
Definition
Pressure above ambient atmospheric pressure produced by an explosion. The peak overpressure and its duration (impulse) together determine structural damage and injury severity.
- Definition
- Pressure above ambient atmospheric pressure from an explosion
- Key related metric
- Impulse (peak overpressure over its duration)
- Determines
- Structural damage and injury severity
- Context
- Explosion and pressure-vessel failure analysis
Common questions
Why does duration matter alongside peak overpressure?+
Two explosions with the same peak overpressure can cause very different damage if one delivers that pressure in a brief spike and the other sustains it longer, since impulse (the pressure-time integral) drives how much energy a structure or body actually absorbs.
How is overpressure damage distinguished from damage caused by fragmentation?+
Overpressure produces broad, blast-wave patterns such as shattered windows or collapsed walls radiating from the source, while fragmentation damage shows as localised, directional impact marks from flying debris, and investigators document both separately during scene analysis.
Related terms
- API 579
- The American Petroleum Institute's Fitness-For-Service standard, which provides assessment methods for determining whether a damaged or corroded pressure vessel or piping component...
- BLEVE
- Boiling liquid expanding vapour explosion. Catastrophic failure of a vessel containing a superheated liquid, producing an expanding pressure wave and, if the...
- Corrosion Under Insulation (CUI)
- External corrosion of a pipe or vessel surface that occurs beneath thermal insulation, hidden from visual inspection, driven by moisture infiltrating the...
- Deflagration
- A subsonic combustion front propagating through an explosive by thermal conduction. Characteristic of low explosives such as black powder and smokeless powder;...
- Detonation
- A supersonic shock wave coupled to a chemical reaction front, propagating through a high explosive at velocities between approximately 4,500 and 9,100...