How’d They Do That?!
In Situ Tower Skirt Replacement
Our final segment of “How’d They Do That” was an exciting project. A key client and manufacturer of personal care products and acrylics have an older ASME pressure vessel column that is a critical piece of equipment in several of their process streams. The column is stainless steel sitting on a carbon steel skirt. Over time, moisture was trapped beneath the insulation and caused a Corrosion Under Insulation (CUI) situation that had left the support skirt thin in some places and deep pits and through holes in others.
The customer was looking to their specialty repair vendors to not only perform the repair, but to help come up with an innovative method to go about the work. After a few site visits and several discussions, we arrived at a plan that we believed could be undertaken safely and quickly. We put the right team together and got to work on planning out the details of the project.
Our scope was to mobilize personnel and equipment, install fully-engineered and third-party verified temporary support structures, then remove and replace the top 12″ of the carbon steel skirt. The final step was to remove the temporary supports and demobilize.
Engineering the temporary supports was not for the faint of heart, as the customer asked that we take into consideration both seismic and hurricane-force wind loading. We ended up with a very narrow tolerance for locating the temporary supports, however execution went very well and, aside from some stress corrosion cracking on the vessel that we dealt with, the project went as expected.
Our competition on this project was looking at using a very large and expensive crane to remove the column from its location, put it on its side and replace the skirt the easy way. Our approach was quicker, less risky and far less expensive than other approaches.
Along the way, we were called out in front of the entire turnaround as the only contractor who was taking safety seriously. This particular client performs daily safety audits and we were the only contractor with a perfect score after almost three weeks of work. The word got out in the area about this repair and we are already talking with other clients with similar issues about repairs on their equipment.
We thrive on the tough projects that no one else wants to undertake and this story is a testament to that. And don’t forget – we love straightforward projects too!
