API 520 or BS2519?

[robhanson]

Hi,

I've just been doing some bursting disc calculations and seem to be getting different answers depending on whether I use API520 (2008 edition) or BS2519:1990.

The value I'm getting with API is around 10-20 times greater than the BS one (there is the factor of 17.9 which would appear to be doing this - I cannot see why the empirical factor is in the API version but not the BS...).

Has anyone got any insight into this? I've attached the sheet I've been attempting to make, and have been over the calculations for about 3 hours, so if they're wrong I'll be pretty annoyed with myself!

Thanks,
Rob

http://files.engineering.com/getfil...4-041feac56be9&file=Relief_Case__eng_tips.xls

 

[robhanson]

I think I've found my answer, I've used bar instead of kPa, bit of a dumb morning there...!

 

[DSB123]

Hi Rob,
Just wanted to point out that the equation you have to calculate Pcf is incorrect. You have the exponent as (k/(k+1)) whereas the formula shows it to be (k/(k-1)).

 

[robhanson]

You can tell it was a Monday when I put it together... Apart from that I think I've got it all sorted now.

Thank you!