4 replies to this topic

[kiran potireddi]

I want to design nitrogen and vent control valve for storage tanks (Floating roof).

I calculated inbreathing and outbreathing calculations.

what i understand:

1. Nitrogen control valve max flow is based on Inbreathing

2. Vent control valve max flow design is based on out breathing.

 

is my understanding right? while design vent control valve- is it needed to sum outbreathing and Nitrogen flow to the tanks

[fallah]

Hi,

 

Do you certain the tank is floating roof type? If so, internal or external one?

[kiran potireddi]

Internal pontono type floating roof

[fallah]

Hi,

 

Then the pad valve (N2 control valve) has to be sized based on maximum flow due to inbreathing (thermal cotraction plus liquid emptying) and depad valve (vent control valve) based on maximum flow due to ourbreathing (thermal expansion plus liquid filling )...

[kiran potireddi]

Thank you Mr. Naser.

API 2000 6 th edition, out breathing calucaltions: As per appendix A- filling rate becomes double (as per liquid factor from table: 2 because my fluid B.P is below 148°c). So when i should consider this calculation.