spark hazard spark hazard KCAn (Chemical) (OP) 28 Jan 15 01:05 Can anyone tell me which could create more spark hazard from the vehicle exhaust pipe in a petrochemical plant or refinery, whether gasoline engine or diesel engine. Thanks in advance RE: spark hazard mbt22 (Chemical) 28 Jan 15 12:32 Gasoline engines are often banned outright. Diesel engines typically have a Chalwyn air intake shutoff valve and exhaust spark arrestor fitted. Matt RE: spark hazard braddles90 (Mechanical) 29 Jan 15 06:07 Diesels and gasoline engines would really have basically the same spark (or ignition) hazards coming from the exhaust pipe in a hazardous environment (hot gas, hot particles would all be similar from an ignition point perspective). Maybe the only slight difference would be exhaust temperatures(?), but once they exit the tailpipe they'd surely be pretty close to each other. The more convincing argument for diesels over gasoline engines is that it's easier to have a fully mechanical diesel (compression ignition) engine running in a potentially hazardous environment in an explosion-protected state than it is for a petrol engine, which requires some electronics to run (spark plugs, etc) which would be a horror to try and get Ex protection for. There might also be arguments for cheaper fuelling if they can supply themselves either petrol or diesel on a refinery, depending on the plant. RE: spark hazard chicopee (Mechanical) 1 Feb 15 04:06 Interestingly enough, exhaust from reciprocating gasoline or diesel engines can be used to maintain an inert atmosphere over flammable vapors in tanks during tank removal. If I am not mistaken, the NFPA used to allow this method years back, however, I have not kept up with this particular regulation so it would have to be rechecked.