Wind girders

[xanthos]

I am a junior Site Engineer for a small Fuel Farm (50000M3). We are now in the time to start installing the wind girders to the 20m height Tanks. The design shown the girders as L180x16 welded on the horizontal flange of the L to the Tank. Also there are grooves for dewatering since this geometry will trap water between the shell and the L.

I don't understand why the Designer shows the L's installed like this. Is there a better alternative in order to avoid the collection of rain water and/or water from the cooling rings?

Thank you

[marian_g]

I am a junior Site Engineer for a small Fuel Farm (50000M3). We are now in the time to start installing the wind girders to the 20m height Tanks. The design shown the girders as L180x16 welded on the horizontal flange of the L to the Tank. Also there are grooves for dewatering since this geometry will trap water between the shell and the L.

I don't understand why the Designer shows the L's installed like this. Is there a better alternative in order to avoid the collection of rain water and/or water from the cooling rings?

Thank you

In API650, the typical details are in Figure 5-24—Typical Stiffening-Ring Sections for Tank Shells.
You can see that normally the design is one which avoid keeping water.

Also in my opinion, using a single L180x180-16 (I never used!) is exaggerate.
As API suggests there are better alternatives (including proprietary design) to achieve the required minimum section modulus, Z.