What is Deflagration?
Deflagration (Lat: de + flagrare, “to burn down”) is a term describing subsonic combustion propagating through heat transfer; hot burning material heats the next layer of cold material and ignites it. Most “fires” found in daily life, from flames to explosions, are deflagrations. Deflagration is different from detonation, which propagates supersonically through shock waves. This means that when a substance deflagrates, it burns extremely quickly instead of detonating. Black powder is an example of a substance that deflagrates; when it is ignited, black powder burns extremely quickly (so fast in fact that the burn is sometimes mistaken for a detonation). Source
If your facility is one where potentially explosive atmospheres, materials or processes exist, it’s likely that you will need some sort of deflagration protection system. The NFPA 68 standard provides advice / recommendations on the design, location, installation, maintenance, and use of deflagration protection devices or systems within a building.
Deflagration protection systems vent the combustion gases and pressures from withing a building or structure so that structural or mechanical damage is minimised after a deflagration event.
What does NFPA 68 address?
Coverage includes a performance-based design option, discussion of the fundamentals of venting of deflagrations, details of deflagration vents and vent closures, and inspection and maintenance. Separate chapters are provided on venting deflagrations of gas mixtures and mists, dusts and hybrid mixtures, and gases and dusts in pipes and ducts operating at or near atmospheric pressure.