Currently, all the blowdown valves are using globe valves (CCI drag valves) and I have tried to trace what is the main reason of using drag valves, however I did not manage to get a clear answer, everyone I asked speculates its due to vibration & the limit of noise of 85dbA in my plant. When I approached my process engineer, he mentioned something else about sound power limit (SPL) which we only can reduce within allowable limits. This SPL is obtained from his process simulation using Hysys software, but my question would be, how do we accept a globe valve which we can only obtain the SPL from our own simulation instead of from the supplier of the valve? I am trying to see if anyone successfully converted from drag valves to ball valves for emergency blowdown application.

Thank you.

 

Consult your valve manufacturer. You'll need the operation data for the valve (fluid, pressure, temperature), and the piping arrangement. All those details are normally provided as part of the process design.