The erosional velocity equation for gas/liquid two-phase lines as per API RP 14E is given as:
Ve = C / (ρm)0.5
where:
Ve = erosional velocity, ft/s
C = empirical constant (100 for continuous service and 125 for intermittent service as per API 14E)
ρm = gas/liquid mixture density at flowing pressure & temperature, lb/ft3
However these values are now considered as conservative and there are certain new guidelines are available for "C" values:
Carbon Steel: 'C' = 135 if nominally solids free (solids less than 1 pound of solid per thousand barrels of liquid); 'C' = 200 or Ve = 65.6 ft/s whichever is lower if totally solids free
13 Cr Stainless Steel: 'C' = 300 if nominally solids free
Duplex Stainless Steel: 'C' = 350 if nominally solids free
I am also posting a link for a paper from the "Society of Petroleum Engineers (SPE)" which also talks about what actually the "C" value is and how conservative the "C" values are as given in API RP 14E. This is really very interesting:
http://www.sand-moni...s/sms_pdf15.pdf
Regards,
Ankur.
Edited by ankur2061, 01 July 2010 - 11:15 AM.