FF SO on shell nozzles

[Syahar1975]

Good morning guys,

Have you ever built the tank with FF SO flange on the shell nozzles ?

In my past experiences in many countries and with many EPC contractors the shell nozzles always RFSO.

 

[geesamand]

Is it a manway, or must it have the full capability of a nozzle?

I see a lot of storage tanks with manways where we install an agitator. The cost of making a raised face adapter flange is much higher than a flat face style.

 

[Syahar1975]

Geesamand,

Yes for shell manhole is very common FF.

But how about other nozzles which will be connected to pipe line outside the tank ? Or instrument nozzles ?

 

[IFRs]

FF or RF is based on the owner's requirements. It depends on the flange that it is bolted to. FF to FF and RF to RF. RF is much more common in my experience. All shell flanges are shown as RF in API 650 but the text does not restrict the user to RF.

 

[geesamand]

I've seen both RF and FF nozzles.

Agree with the others - do not mix mountings. The flat face can "lose" that battle under bolt torque.

 

[11echo]

The tanks we deal with we have PRESS/VAC reliefs (mushroom cap type) they are made out of aluminum and come with a F.F. Flange ...so we supply one to deal with the bolt up.