what is Dip Ring?

[PogingLamig1]

Dear ALL,
In this paragraph what is the meaning of Dip Ring?
5.4.5 If specified on the Data Sheet, Line 12, a foundation drip ring shall be provided to prevent ingress of water between the tank bottom and foundation. Unless the Purchaser specifies otherwise, the ring shall meet the following requirements

-The drip ring shall extend at least 75 mm (3 in.) beyond the outer periphery of the foundation ring wall and then
turn down (up to 90°) at its outer diameter.

Thanks..

 

[NBrink]

See figure 5.5 in API 650, it makes it abundantly clear what they're talking about. Basically it's a sheet of metal that is welded to the chime and extends beyond the foundation to prevent water ingress.

Have never actually seen one on a tank, but I imagine they get more use in wet areas...

 

[PogingLamig1]

Sir NBrink i appreciate your response but i have one more question, do we have a distance restriction or minimum in outside diameter of shell going thru OD of annular plate?