PVRV design

[appy11]

Hi,

I am sizing one of the PVRV on supply line. I got equations and charts to be utilized for calculating inbreathing and outbreathing flow for the system (from API 2000). But how to determine set pressure (vacuum) during inbreathing condition.

any inputs??

Thanks

 

[Latexman]

Since you did not give any information on your application at all, I'll blindly say that in general a good starting point is make the "set vacuum" about 1/4 the "design vacuum" and size the system so the "actual vacuum" is about 1/2 the "design vacuum".

Good luck,
Latexman

 

[appy11]

Latexman,

your answer is more confusing than my question. This PVRV is to be designed for Water supply header and to be protected under drain out condition. Ihave water flow rate and other conditions but don't know how to determine set pressure (vacuum side).Pipe specs say pipe can withstand 0 bar(g) pressure, but I have seen lower set pressure for the same configuration. please advice

thanks

 

[Latexman]

Then I will confuse you no further.

Good luck,
Latexman

 

[CJKruger]

appy11, actually Latexman gave a very good reply assuming you are protecting a tank. Frankly, it is not often that we protect piping against vacuum.