API650: F&D Head min thick calc.
API650: F&D Head min thick calc.
(OP)
Hello to all, and Thank you in advance.
I have a design for a 9'dia x 25'OAH 316LSS Decarbonator to be built per API 650/S Code. My question is how do I calculate the min roof thickness (F&D Head)?
The tank is at atmospheric pressure, and and has a max liquid level of 6ft (overflow outlet), and a design Roof Live Load of 25 psf.
Any help or insight would be great, as I am new to the ways of "the Code."
I have a design for a 9'dia x 25'OAH 316LSS Decarbonator to be built per API 650/S Code. My question is how do I calculate the min roof thickness (F&D Head)?
The tank is at atmospheric pressure, and and has a max liquid level of 6ft (overflow outlet), and a design Roof Live Load of 25 psf.
Any help or insight would be great, as I am new to the ways of "the Code."





RE: API650: F&D Head min thick calc.
Use the method in API-650 to calculate the head thickness. For an F&D head, use the method for thickness calculation of a "domed" roof (a similar shape).
If the head shape is an "ASME F&D" shape (there are different types of F&D heads) you can use the equation in ASME VIII to calculate the thickness. Use 2.5 psig as the design pressure. (Bytheway, an "ASME F&D head" has curvature requirements....it is also sometimes called a "torospherical head")
What is your roof loading ? Snow ? Deadload ? Wind ? The API-650 code also contains minimum design loads for tank roofs (about 25 psf....as I recall)
Are you going to try to design, test and fabricate this tank yourself or what ?
This is the kind of question that a fabrication shop would know how to answer. Perhaps you could just "spec out" this small tank and get one priced and delivered ?
Hope that this helps
MJC