Pipe Flow Calculations Forum

Hi Folks,

I am trying to calculate what size of outlet is needed to keep a vacuum from occuring in a tank. Basically what happens is during cleaning of the tank the inside is cooled quickly and causes a pressure drop within the tank. From my research so far I have come across how to calculate it but I seem to be missing the "required relief capacity". I'm not sure what exactly this is or how it is found, any help on this would be much appreciated.

Thanks,

Hugh

You must know how "quickly" it is in order to calculate flow rate of air required and pipe diameter needed for it.
When you know time t that is needed to drop temperate from one point to another you can calculate how much volume ( V ) is changing in that time and from there you have flow rate (Q=V/t). For that flow rate check the diameter. Also pressure in the tank when temperature is low is needed as in that moment flow rate is in maximum.

Ah I see, yes that makes sense now. Thanks very much