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FIRE SAFETY => Dangerous Substances Explosive Atmospheres => Topic started by: jasper on September 08, 2016, 03:41:05 PM
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I was wondering if there was any way of cross referencing calculations for DSEAR. I have been doing a desktop study on the release of LPG, Propane and Hydrogen cylinders stored internals. I have done the simple bit of type, rate of release and zone classification etc. but want to check my calculations for hypothetical volumes of release.
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There are many different approaches and which may be relevant depending on the circumstances.
As a starter you might want to look at BCGA GUIDANCE NOTE GN13 "DSEAR Risk Assessment". It includes some estimates of Zone dimensions based on various scenarios.
For a more in-depth analysis of the leaks and the impact of ventilation then the use of the HSE's Quadvent software may be appropriate.
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Thanks for the reply Al, to be honest I wanted a bit more detail in my assessment rather than just using prescriptive guidlines
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GN 13 isn't a prescriptive guideline it includes data from CFD modelling of gas releases which would allow you to review your initial assessment. Quadvent is HSE software based on detailed research and testing for natural gas releases. It goes beyond the relatively simple approach in the earlier versions of EN 60079-10.
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This is a very good document however this only looks at outdoor storage not indoor
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You probably have no option other than to carry out some fundamental leak calculations, using EN 60079-10, or using Quadvent. Ultimately the zoning will be very much dependent on the leak rate, room size and ventilation rate/efficiency. However, in many cases all you end up proving is that the prescriptive guidance is correct in the case of poorly designed or protected installations, i.e. those without adequate ventilation or containment & extract.
Off on holiday now, so good luck in resolving your challenge.
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Jasper
Would be happy to sanity check any calcs
Regards
Bleve