THICKNESS OF RAFTERS IN API 650 TANKS
THICKNESS OF RAFTERS IN API 650 TANKS
(OP)
Hello
I am new in the design of storage tanks and I have somes question about it.
In the API 650, item - 5.10.2.4 "Structural Member Thickness: All internal and external structural members shall have a mininumm nominal thickness(new) of 4.3 mm (0.17 in.), and a minimum corroded thickness of 2.4 mm (0.094 in.)"
1) are the rafters included in the structural members ?
2) Do the rafters must have that minimum thickness?
3) What kind of beams are usually used as rafter?
I am new in the design of storage tanks and I have somes question about it.
In the API 650, item - 5.10.2.4 "Structural Member Thickness: All internal and external structural members shall have a mininumm nominal thickness(new) of 4.3 mm (0.17 in.), and a minimum corroded thickness of 2.4 mm (0.094 in.)"
1) are the rafters included in the structural members ?
2) Do the rafters must have that minimum thickness?
3) What kind of beams are usually used as rafter?





RE: THICKNESS OF RAFTERS IN API 650 TANKS
2. Yes. Interestingly enough, the thinnest web of a W Shape in the AISC Steel Construction Manual has a thickness of 0.17 in. (W6x8.5). Also, the thinnest web of an S Shape is 0.17 in. (S3x5.7).
3. W Shape and Channel are the most common rafter shapes that I have dealt with, although it is possible to use T Shapes, Angles, or some other shape if you are so inclined. Only a two of the Channels have a web thickness thinner than the minimum (C3x3.5 and C4x4.5).
RE: THICKNESS OF RAFTERS IN API 650 TANKS
I have anothers questions,
Is mandatory the use of corrosion thickness for the rafters or is that a design criteria?
Could I use S shape underside W shape ?
RE: THICKNESS OF RAFTERS IN API 650 TANKS
Yes, any combination of shapes that satisfies AISC 360 will meet the requirements of API 650.
RE: THICKNESS OF RAFTERS IN API 650 TANKS
RE: THICKNESS OF RAFTERS IN API 650 TANKS