Last month, we continued our discussion about how some equipment just can’t be revived and referenced an actual ongoing project. The head had suffered from Stress Corrosion Cracking (SCC) under the half pipe and the cracking was severe enough to condemn the unit due to these issues. The only path forward to save the reactor vessel was to check the adjoining area of the head via phased array UT and, if the areas outside of the central section of the head was in good condition, it might be possible to cut out and replace the center/dished section of the head with new half pipe pre-installed without worsening the SCC.
That phased array UT inspection was completed and, as it happens, the rest of the vessel and head was in good condition and the course of action is to cut out and replace the dished section of the head with new half pipe. There will be a complex rigging plan to move the new head through the plant and get it in place for welding. The repair will be to make a single ~72” diameter butt weld with 100% RT to get this customer back in business using this reactor again.
Although all equipment cannot be rescued, with the right craft personnel, design expertise, ASME Code knowledge and determination, it’s not unheard of to extend the life of your equipment without going through the expense and schedule interruption of ordering a new vessel.