pressure relief valve for daily temp variations?

[tristrium1]

I am working as the client in Africa on a number of petroleum storage facilities. A typical facility consists of 5 by 200m3 jet A1 tanks built in a row with a issue line connecting them at the back and a receipt line at the front. The issue and receipt lines are typically 40m long subdivided into 3 sections by gate valves. The independant engineer claims that we need pressure relief valves for the thermal effects during the day while the supplier claims we do not. I would tend to agree with the supplier as the max pressure from the tanks is 80kPa and these are thick 3 inch pipes that have been pressure tested to 15 bar. I would like to get a third opinion though.

 

[BigInch]

Never agree with a supplier. You will be wrong every time, just as you are here.

Let your acquaintances be many, but your advisors one in a thousand’ ... Book of Ecclesiasticus

 

[gr2vessels]

I would suggest to make an engineering decision based on facts, rather then outside advices without a basis. Did any of them support their claim with calculations? Has either of them quoted any standard or code clause? PRV required or not, you must provide to your Client/management supporting engineering calculations for either way and advice from supplier or this forum is not enough.
Cheers,
gr2vessels

 

[dcasto]

do not use relief valves, use a 1/2" check valve around the 3 block valves.

Yes, sun shine on a blocked in line will cause an over pressure, but the check valve will open and let 3 cc's out dropping the pressure.

 

[BigInch]

With all those check valves, how do you shut off flow to the tank?

Let your acquaintances be many, but your advisors one in a thousand’ ... Book of Ecclesiasticus

 

[Compositepro]

The check valves would be relieving pressure in the upstream direction. There may still be a need for one relief valve at some point.

 

[BigInch]

Ya. Precisely where I want product to go.

Let your acquaintances be many, but your advisors one in a thousand’ ... Book of Ecclesiasticus