Fuel Oil N¦ 6 vapor pressure

[rkuhn]

Hi,

I need the vapor pressure value for:
- Fuel Oil N°6 at 140°F ( known also as Buncker C )
- Diesel at 68 °F

Thanks

 

[TD2K]

What do you need them for wrt how accurate? Neither have a defined or fixed vapor pressure as such. For valve sizing (where the program needs a vp to check for vapor pressure) and for pump NPSHA calculations, I've used 0.1 psia for diesel. For #6 FO, it's also in this range unless it's pretty hot.

The other way is to back estimate it off the flash point. A lot of HCs have a LEL of about 1 to 2%. If the flash point is 150F, that works out to about 0.22 psia vapor pressure (using the average of 1.5 mol%) at the determined flash temperature and then you can adjust it for the temperature you need.

 

[rkuhn]

Thanks TD2K,

I'm doing NPSH calculations. I'll use the 0.1 psia and hope no bubbles will be present at the pump !!