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Can somebody share his experience on butt weld insert plate in a pressure vessel?
We are performing a repair in our pressure vessel by inserting a rectangular plate by replacing a locally corroded plate area. Just want to know some considerations necessary to be taken during the welding of the same.

It's a complex welding.
1. The welding is applied without a gap and a maximum tip height (root) of 2-3 mm.
2. The corners are rounded off with a minimum roundness of 5t with or 50 mm whichever is greater.
3. The welding sequence shall be cross that is starting from one vertical half then the opposite other half
4. Vertical seam must be finished first then come to the horizontal ones again in the manner described in point 3.
5. Corners shall be welded at the end to prevent shrinkage which may cause cold cracking.
6. Internal supports must be used to prevent any deformation.

Thanks.
Can you share any figure illustrating the sequence of welding?

Few Guidelines for Butt Welded Insert Plates as per RepairShop Software / ASME PCC-2 (Article 2.1)
1. Full penetration butt welds are made with close fit of insert plate is mandatory.
2. Insert plate should be of the same P-number and thickness as that of pressure component.
3. Double welded butt welds are recommended (where possible).
4. For single butt welded insert plates, root pass shall be made with GTAW.
5. 100% RT (if practical) or 100% UT alongwith 100% MT or 100% PT is recommended for both root & final pass.
6. PWHT if required by thickness or service is to be carried out.
7. Pressure testing (if possible) is to be done.
8. For more details, refer to ASME PCC-2 Article 2.1

Thanks qaisarabbas.

In our case, we have to insert a rectangular butt welded insert plate and interested in knowing about the correct welding sequence.

Here is the welding sequence which may help you out.

Thanks ashfaq.