Vacuum pressure at 60" inch diameter carbon steel pipe

[Lasuen]

Hi,

I am mecanical engineer and currently piping designer at an oil refinery.I would like to knw if there is a calculating method for determining vaccum presure and metal designing temperature when a large and big pipe is conected with a tower while it's being vaporizating prior to a unit shutdown.

When determining if vaccum can exist, I should design under ASME VII.¿BUT HOW TO EVALUATE IF VACCUM CAN EXIST? and wich will be temperature value in the design ¿should be that value, the condensating temperatura at vaporizating presure?

Thanks a lot

 

[TD2K]

Talk to your process engineer. They will be able to tell you if vacuum can exist, what maximum vacuum should be considered and the corresponding temperature. Then you also have maintenance or commissioning activities, if they involve steam-out that's another potential source of vacuum which if it's an issue, has to be addressed either in the design of the vacuum capacity or means to prevent it.