blowdown Line Sizing

[chemiind]

What is the criteria for sizing inlet and outlet blow down lines on process equipment. I think the RO size has to be restricted to 0.2 beta ratio, but what about the mach number.

 

[maddocks]

Obviously lower the better, but you'll be in critical flow so I would restrict to mach 0.7. Beta size can be whatever you need for the proper time and flowrate given your initial DP.