ERECTION OF THREE STEEL STACKS

Industrial Access performed erection and installation services of three new carbon steel exhaust stacks of up to 334’ in height. The client needed a crew of experienced engineers and technicians to handle installation of access scaffolds and welding of splices in between stack sections. Industrial Access has decades of experience in delivering stack erection, repair and maintenance services across North America.

A chemicals facility was in need of stack erection services for three single-wall carbon steel stacks of varying heights – 150’, 334’, and 199’. Industrial Access (IA) was contracted to provide scaffolding, labor, and tools to perform full penetration splice welds between sections of the stacks during the process of assembly and erection. The foundations with first connections for each stack were prepared by the client prior to IA’s mobilization.

In order to carry out this work, every stack section required a temporary platform to provide safe stack access and support for IA welders and technicians. To accomplish this, a single scaffolding system was built prior to enable platform assembly for each section. Cranes would place a stack section inside the scaffolding, where IA crew would install a temporary platform near the top of the section, and then a crane would lift the section and align it with the stack already installed below. The crane was also utilized to carry building materials as well as lift a man basket transporting the crew to and from the stacks in progress, as arranged by the client.

A total of fourteen stack sections were pre-fabricated and transported to the site. The first stack comprised of three sections, the second stack comprised of seven sections, and the third—of four sections. Once each stack section was lifted into final position, the erection bolts were installed and adjusted to verify that the section was plumb. To prepare splice surface, the edges of the two sections to be spliced were cleaned with tools to remove oxidation. Where required, the edges were ground to provide the requisite gap at the weld root. As new sections were brought in, temporary alignment rods were installed to keep them safely in place. Then, IA performed splice welds, which were accomplished in several passes to provide complete joint penetration in accordance with the client’s design drawings. A total of eleven splice welds were completed.

To ensure structural integrity and stability of each stack, tuned mass dampers were to be installed. They were bolted in on the top section of each stack while at grade, prior to splicing the section to its final position. In addition, any temporary erection bolt mounting brackets and other installation aids were cut out, and surfaces were ground smooth. Temporary shipping spiders were removed from each section as well during the assembly.

The project was completed safely, efficiently and within budget. All three exhaust stacks were assembled successfully, ready to use. Moving forward, it is critical to perform regular inspections and timely maintenance in order to prevent unchecked wear-and-tear turning into extensive and costly failure. IA is expected to return to the client’s facility to provide professional, quality services and perform an inspection for another of their structures. Industrial Access helps their clients maintain the safety and longevity of their smokestacks.