InspectorJ
Mechanical
- Jun 16, 2022
- 1
Hello all. I'm new here but have a question that maybe someone here can help with.
I have a 54" carbon steel nozzle on the top head of a large PV that is internally lined with corrosion resistant inconel overlay. There is severe external corrosion around the circumference of the neck to the extent that the internal inconel overlay is visible is several locations. This vessel operates with 100% shell water coverage at all times and the corrosion is located at the turbulent water introduction point.
My recommendation is to replace the nozzle due to the fact that corrosion resistant overlay does not count as a pressure boundary. Essentially, the nozzle is holed through. Management is asking me "why can't we weld build up the wasted areas back to nominal thickness?"
Does anyone know where in the codes I can show them that it is not allowed or that it is not recommended to use internal overlay as "backer" to restore the pressure boundary?
OR is this type of repair allowed??
Thank you.
I have a 54" carbon steel nozzle on the top head of a large PV that is internally lined with corrosion resistant inconel overlay. There is severe external corrosion around the circumference of the neck to the extent that the internal inconel overlay is visible is several locations. This vessel operates with 100% shell water coverage at all times and the corrosion is located at the turbulent water introduction point.
My recommendation is to replace the nozzle due to the fact that corrosion resistant overlay does not count as a pressure boundary. Essentially, the nozzle is holed through. Management is asking me "why can't we weld build up the wasted areas back to nominal thickness?"
Does anyone know where in the codes I can show them that it is not allowed or that it is not recommended to use internal overlay as "backer" to restore the pressure boundary?
OR is this type of repair allowed??
Thank you.