Thanks, CMA
I used API 521, and the got the Mach number 0.466. the pressure drop is almost same, around 3.8 Kpa.
http://files.engineering.com/getfile.aspx?folder=4a5fef74-c780-4e88-9120-9b2b776ca882&file=Built_-_Up_Back_Pressure.xlsx
Hi Latexman,
Thanks again for your quick reply. It is a 3 in NPS venting pipe with 2 meter long
I found a error in my calculation before. Now I got three different results:
(1) using D-W, read friction factor from Moody Chart (0.015), I got 3809 Pa pressure drop
(2) using D-W, calculate...
Thanks for the reply.
I used the D-W equation. For 2 m pipe, 1884 scfm and I got the pressure drop to be 3.1 KPa.
I also used Panhandle A equation, and the pressur drop 0.02 KPa.
What might be wrong in my 2 calcuations?
This is a natural gas PSV. Though the discharge is to atmosphere, there will be little increase in back pressure on PSV. I remember there is an equation to calculate this. Can anyone please give me a hint?
Thank you!!