Dear All,
During a job we've faced a problem with sizing relief valve for unwetted gas vessel containing ethylene - nitrogen mixture @ 1barG, 34 degC (554R).
The relief valve is set @ 11 barG and thus of this the relief temperature according API 521 guidelines, calculated as T1=p1*Tn/pn is quite above 1400 degC (3128 R).
The relief area cannot be calculated acc to API 521 due to the fact that Excel cannot calculate the value of (1559-3128)^1,25, where 1559 is max wesell temp for steel.
Do You have any idea how to calculate such a case?
Any help will be appreciated.
Edited by Beergson, 24 January 2017 - 02:50 PM.