Cracks in Incinerator Recuperator – Failure Investigation & Repair

When cracks occurred in a incinerator recuperator at a chemical plant – we were asked to investigate. The cracks had developed through the ligaments of its tubesheets – causing significant leakage. We determined that severe differential thermal expansion between the heavy steel frame, which provided peripheral restraint, and the perforated tube sheet had caused tearing of the numerous tube sheet ligaments.

Analysis confirmed that the initial failure of a single ligament had caused almost instantaneous progression of the failure through rows of ligaments. We designed a repair of the failed unit, consisting of inserting and rolling sleeves in the ends of the existing tubes where the tubesheet ligaments had cracked.

These inserted sleeves were then seal welded to the original tubes and a stainless steel pad was applied to the tubesheet to both seal the cracked ligaments and strengthen the tubesheet for temporary operation.

O’Donnell Consulting Engineers Performs Failure Analysis for Clients in Industries including Energy, Manufacturing and Petrochemical.