Drain pipe design
Drain pipe design
(OP)
I am assigned to design a spill way for LNG tank. It is to drain LNG in case flange failure. While sizing the vertical drain piping, I was told to use self-venting design which limites froude # <0.3.
My questions are:
1. If design for full flow(froude # =0.8), is it acceptable? what bad will happen?
2. Is that necessary to design for self venting for this never or once in the tank lifetime scenario? The reason is the cost difference betw 12" and 20" SS pipe.
Thank in advance.
My questions are:
1. If design for full flow(froude # =0.8), is it acceptable? what bad will happen?
2. Is that necessary to design for self venting for this never or once in the tank lifetime scenario? The reason is the cost difference betw 12" and 20" SS pipe.
Thank in advance.





RE: Drain pipe design
RE: Drain pipe design
Katmar Software
Engineering & Risk Analysis Software
http://katmarsoftware.com
RE: Drain pipe design
Taking it at face value that you want to drain LNG. If the line isn't self venting the vapourising LNG would most likely vapour-lock the line, or at least massively restrict the flow.
As for whether it's necessary to design for a rare event, if you need this as mitigation for equipment failure, you need it to work.
Matt