Hi all,

I am working for blowdown-depressuring study for an existing facility's expansion. I performed the depressuring runs for it and now trying to give the data to an vendor to size the related RO's for blowdown. I have some questions, if anyone can update with any hint it would be great for me.

1) While filling up the RO-datasheet which properties should I put? Is that the Peak-flow properties or stream properties of inlet to BDV (RO) or stream properties of outlet of BDV (RO).? & WHY?
2) What would be the design pressure for the RO? is the same as the operating pressure of the upstream vessel or again the stream pressure/peak pressure?
3) If the stream is all vapor but in some cases it gives a liquid in-between or at the end of depressuring. Should I take the "liquid-phase properties' from that liquid stream or should simply say there is no liquid? WHY?


Any suggestions are welcome!

Thanks in advance.

1. Theoretically you have to find the size for RO for all pressure level and fill in the pressure level which gave you maximum bore size. However generally it occur during peak flow (not necessary peak pressure).

2. Design pressure same as protected system.

3. This tie to item 1. Generally lesser (nearly no) concern at the end of depressuring.

Thanks much JoeWong.
Its pretty clear to me now.

"2. Design pressure same as protected system."---could you please explain what"protected system"means?

Thanks again!


Regards,

It mean the system where BDV/RO is connected (source).