Agenda Item 650-587
Title: Joining narrow shell plates to form wide ones.
Source: E-Mail from Marty Herlevic
Handled By: Marty Herlevic
Phone: (318) 322-6104
Fax: (318) 388-4245
Legend: new text
API 650 10th Edition Addendum 2 – Appendix S
Two stainless steel plates identical in material type may be welded together prior to erection in order to form a single shell plate subassembly. Plates welded together shall have thicknesses within 1/16” of each other with the maximum plate thickness being 1/2”.
Each plate shall be a minimum of 48” wide and a maximum of 60” wide with No more than two plates being shall be used to form one subassembly. Vertical edges of the pair of plates comprising a subassembly shall be aligned. The vertical joint offset requirement of 184.108.40.206 (b) shall be applied only between the subassembly and plates above and below it. The subassembly shall conform to the dimensional tolerances contained in Section 5 and shall be subjected to inspection requirements contained in Section 6. At least 25% of vertical spot radiographs shall be made at the subassembly horizontal weld to field vertical weld intersection. All welding procedure specifications shall be in accordance with Section 7.
COST IMPACT: Owner/Operators will save money on material by going to narrow plates in lieu of 72” wide. It is less expensive to purchase narrow width plates and perform the additional welding required.
TECHNICAL BASIS: None