Sending vapor line to liquid line
Sending vapor line to liquid line
(OP)
I am currently working on a design of storage vessel pressurized with nitrogen. My team decided to send the vent Line to liquid line at the discharge of pump. I have never seen vent line connected to liquid line. I appreciate if anyone can explain if this is a good or bad design.





RE: Sending vapor line to liquid line
Good luck,
Latexman
RE: Sending vapor line to liquid line
I would want to look at where the vapor is going to go, obviously the destination has to be able to handle it. A floating roof tank wouldn't be a good destination. How much vapor do you plan to send to the line, is it going to affect the hydraulics adversely? What if the pump isn't running, the pump is going to start up the next time with perhaps a line with a lot of vapor. Any pressure concerns or different pipe spec issues from connecting these two systems together? Any production specification issues? Just a few things I would want to think about.
RE: Sending vapor line to liquid line
Just a thought,
sshep
RE: Sending vapor line to liquid line
RE: Sending vapor line to liquid line
Still as Latexman said P&ID is a must.
To correctly analyze,guide/attempt for problem resolution with particular details e.g.
Where is the subject liquid pipeline's routing/final termination point i.e. going through some vaporiser to flare system or elsewhere??
Best Regards
Qalander(Chem)
RE: Sending vapor line to liquid line
Good luck,
Latexman
RE: Sending vapor line to liquid line
RE: Sending vapor line to liquid line
It looks like the recirculation line ties in *upstream* of the pump filter...
Maybe its just me, but from the sketch, there isn't enough information for me to piece together what they are trying to do. If the pump at the bottom of the page runs continuously then, depending on the N2 pressure on the vessel (is it higher than 206 psi?) the intent might be to blowcase the collected drained liquid into the downstream tank where, presumably, the blanket N2 pressure is much lower.
Given the temperatures and the fluid (heat transfer fluid?) involved, part of me, at least, thinks that a corrollary intent might be to make sure that N2 is in the system in preference over air in order to stay below a lower flammability limit.
RE: Sending vapor line to liquid line
Good luck,
Latexman
RE: Sending vapor line to liquid line
You want to to take the N2 used to run the blowcase and vent it into the tank. Wow, talk about anal, what the heck is in that heat transfer fluid that a few ppm when vented into the air will harm anything? If it is that bad, it will vent out of the top of the tank eventually.
You do realize if the tank (the storage tank) is full, you may only be able to vent the blowcase down to say 15 psig and you will have to vent that to the atmosphere.