Deflagration pressure containment

Design system for deflagration pressure containment where practical... 

Deflagration pressure containment is an approach for selecting the design pressure of a vessel so that it is capable of withstanding the maximum pressure resulting from an internal deflagration. Vessels or process equipment can be designed to either... 

NFPA 69 (1997) provides equations for calculating the required design pressures for both types of containment design. It also discusses the limitations of deflagration pressure containment design. 

Noronha, J. A., J. T. Merry, and W. C. Reid, "Deflagration Pressure Containment (DPC) for Vessel Safety Design," Plant/Operations Progress, 1,1 (1982). 

Deflagration pressure containment is a technique for specifying the design pressure of a vessel and its appurtenances so that they are capable of withstanding the pressure that results from an internal deflagration. This may be inherently safer than relying on techniques to prevent deflagrations. These techniques are not to be used to contain a detonation. The ASME Boiler and... 

Pressure containment can also be provided by using piping systems with a pressure rating above the anticipated maximum pressure generated during a deflagration. 

Fig. 9.30 Diagram of HAM deflagration pressure attenuation [7] 7 - 5.3 m container with HAM 2 - protective wall of 4 m in height and 10 m in width...

The pressure developed by decomposition of acetylene in a closed container depends not only on the initial pressure (or more precisely, density), but also on whether the flame propagates as a deflagration or a detonation, and on the length of the container. For acetylene at room temperature and pressure, the calculated explosion pressure ratio, / initial > deflagration and ca 20 for detonation (at the Chapman-Jouguet plane). At 800 kPa (7.93... 

The measured explosion pressure ratio for deflagration in a container only a few diameters in length approaches the theoretical value often it is about 10. However, in a pipe hundreds or thousands of diameters in length, deflagration may cause very tittle pressure rise because only a small fraction of the contents is hot at any time. 

For reactors containing flammable liquids, where the reactor design pressure is insufficient to contain a deflagration, consideration should be given to providing an inert gas blanket (usually nitrogen). 

Maximum Pressure and Rate of Pressure Rise and KJ These explosibility parameters are used in assessing whether equipment will contain the maximum pressure developed during deflagration, or to design deflagration relief vents and other explosion prevention systems (see NEPA 68 and 69). The test method is given in ASTM E 1226. 

Explosion The bursting or rupturing of an enclosure or container due to the development of internal pressure from a deflagration or detonation. 

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