I would like to ask your suggestion that In-service welding can be applied on 1” line, class 150, thickness 6.11 mm or not krub.
As per attached anomaly report, we found 2 severe corroded points under U-bolt [No. 3-4].
The online repair method as usual, composite wrap was not recommended since the removal of u-bolt has high risk to crack pipe as per consideration on present condition.
So, AI SMEs recommended that we can do online repair by
1. Install temporary supports and cutting existing support.
2. Apply welded full encirclement repairs with end plate method cover both pipe and u-bolt with support. [See attachment]
Anyway, this method has some concern points as follows.
1. Hot work for in-service welding is required to weld end plates on pipe.
2. Control flow in this pipe cannot be applied because it connects to closed drain header.
3. Pipe thickness is only 6.11 mm.
Please kindly let me know, if you have any comments na krub,