API620 IFR

[rikywere]

Dear Sirs,
Has anybody seen a low pressure tank (API620, DP=0.6barg) with internal floating roof? Does it make any sense? If yes, please explain the sense of this configuration. How do you keep the pressure balanced between above and below floating roof?
Thanks in advance

 

[Duwe6]

Floating roofs float. They do not seal tightly, thus pressure will balance.

Since the fluid, both liquid and vapor are contained in the 620 vessel, why would a floater improve anything? A floating lid should work well, but I see no sense in it. Please explain?

 

[rikywere]

I cannot explain. From my point of view It does not make any sense neither. I have never seen it and I do not see any reasons to use it. But client asked if possible and I did not find any reason not to use it except because it is useless. Useless but not harmful.My answer will be: yes you can but it is a complete waste of money.
Lots of thanks,

 

[IFRs]

The floating roof might lower the concentration of product vapor in the space above the floating roof.

 

[mariog123]

Some guidance in API 650, H.5.2.2.3 If circulation vents (per H.5.2.2.1 and H.5.2.2.2) are not installed, gas blanketing or another acceptable method to prevent the development of a combustible gas mixture within the tank is required. Additionally, the tank shall be protected by pressure-vacuum vents in accordance with 5.8.5, based on information provided by the Purchaser.