2 replies to this topic

[Tolinorton]

What is the difference between Vapor pressure exception and Vapor pressure waiver of gasoline.

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•  Pages from EN 228-2012.pdf   99.08KB   11 downloads

[Pilesar]

If I understand your question correctly, I explain it like this:

Gasoline has vapor pressure specifications. But when ethanol is included in gasoline, the normal vapor pressure specifications are difficult to meet.  So there is an allowable exception to those specifications when ethanol is in the gasoline. Even with ethanol in the gasoline there are still vapor pressure specifications that must be met based on the amount of the ethanol component. The amount of ethanol determines how much higher vapor pressure is allowed. The revised vapor pressure spec value is calculated from the table you attached. This new vapor pressure is specific to the composition of your gasoline and is the amount of 'vapor pressure waiver' allowed if the gasoline does not meet the normal gasoline spec.

[Tolinorton]

Dear Pilesar,

 

Thank you so much for the answer, I just wanted to know is there nay differences between Vapor Pressure Exception and Vapor Pressure Waiver.