Tank Horizontal joints

[nabeel3]

Dear Experts
Para 5.1.5.3 of 2020 Edition says "Unless otherwise specified, abutting shell plates at horizontal joints shall have a common vertical centerline". I am trying to understand it, but my relatively little experience in Tanks makes it difficult to understand. Any good Samaritan can help me to understand this , if possible with a picture

 

[HTURKAK]

Pls look (Figure 5.2—Typical Horizontal Shell Joints ).
Notice that the vertical centerlines of shell plates at horizontal joints matches and have a common vertical centerline.

Use it up, wear it out;
Make it do, or do without.

NEW ENGLAND MAXIM

 

[nabeel3]

Thank you ,

 

[IFRs]

While the default unless otherwise specified is center stacked, it is not uncommon for owners to specify shell plates to be inside aligned (flush inside) if there is to be a floating roof.