Minimum Shell Course Width for API 650 Tank
Minimum Shell Course Width for API 650 Tank
(OP)
API-650, para. 5.6.1.2 said "Unless otherwise agreed to by the Purchaser, the shell plates shall have a minimum nominal width of 1800 mm (72 in)".
Does this requirement apply for all of the shell courses? (which is not practical) Or it apply only to 1st course welded to bottom plate ?
Our client is pointing out this requirement, which is not practical for us to follow because the total height of the Tank.
What will be the best solution to answer ?
Thanks
Does this requirement apply for all of the shell courses? (which is not practical) Or it apply only to 1st course welded to bottom plate ?
Our client is pointing out this requirement, which is not practical for us to follow because the total height of the Tank.
What will be the best solution to answer ?
Thanks





RE: Minimum Shell Course Width for API 650 Tank
RE: Minimum Shell Course Width for API 650 Tank
In the US, plate is commonly available in 120", 96", 72", etc. and that availability is assumed to some extent in the standard. You can avoid using a narrow course at the top by using wider courses on the other rings.
Actual widths used are based on availability, cost, labor cost, etc.
I've seen some overseas jobs where the available plate was 1500mm, and you just design and detail accordingly.
The main issue to watch out for is if the bottom ring is too narrow, the manway repads will hit the first seam.
RE: Minimum Shell Course Width for API 650 Tank
The Tank height is 4300 mm Dia x 5300 mm H.
I asked API for it (whether this requirement "minimum shell course shall be 1800 mm" should applicable for all shell courses or Only bottom shell course) but I got the reply that "API is not able to provide an answer to your inquiry because API does not provide consulting on specific engineering problems or on the general understanding of its standards".
Seem I have to seek for our Client's approval.
Thanks & Have a nice day.
RE: Minimum Shell Course Width for API 650 Tank
RE: Minimum Shell Course Width for API 650 Tank
The MOC is Carbon Steel.
We had the discussion today. Hope it will be approved.