API 650 Tank Roof Plate Thickness

[MOHAMMED89]

Dear All,

Is there any requirement as per API 650 regarding the thickness of roof plate for supported cone roof?
We are planning to use 6mm plate and 7.5mm plate for the supported cone roof, So my question is "Is it possible to use two sheet of 7.5mm and rest 6 sheet of 6mm plate for the Supported cone roof tank.

I have check in API 650, But I didn't find any clause for the above query.


Thanks in Advance

 

[JStephen]

The standard specifies minimum thickness, but doesn't require all plate to be the same thickness. You'd need to consider the extra thickness in the design for rafters and center column.

 

[MOHAMMED89]

Thanks A lot Jstephen,

The rafter design found safe.