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[MW:4369] STORAGE TANK NOZZLE WELD STRESS RELEIVING

By Materials & Welding
Hi all,
 
A storage tank nozzle with pad plate welded to shell required to be stress relieved as a prefabricated assembly (Material Group IV A), and the assembly has to be installed in the Tank as per API 650. But the contractor missed the same and Tank erection is completed now. Contractor cut the hole and welded the nozzle.
 
Now only option is to cut & remove the shell plate, stress relieve and reinstate. But they fear the dimension and shape of the tank may be adversily affected.
 
Local Stress relieving is not permitted as per API 650.  Anybody ever came across a similar situation, and please give details how to solve the problem.
 
Nandagopan

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