Spotlight Projects:

The Hopper Engineering Associates team provides practical and exciting solutions to unique problems in several industries. To showcase our recent work we choose a project of the month. An archive of previous winners can be found here.

Spotlight Project:

Heat Exchanger Tube-to-Tubesheet Weld Failure
Heat Exchanger Failure
Challenge:

Significant cracking of tube-to-tubesheet welds was observed after start-up testing of a fixed-tubesheet heat exchanger in the cracked gas/boiler feed-water service. Multiple tasks were required to determine the cause of the cracking, the viability of the original design, and the acceptability of a proposed weld overlay repair.

Resolution:

Our engineering team performed ASME Section VIII Division 2 design analyses of the tubesheet region to determine the viability of the original design. The analyses included a detailed 3D finite element (FEA) model of the vessel which took into account material plasticity. Heat transfer analyses resulted in continuum temperature distributions, which were used to evaluate material properties and to determine allowable material stresses. A proposed weld overlay repair was also evaluated. This task included crack growth and brittle fracture analyses to determine the potential for existing weld flaws and cracks to propagate upon subsequent hydrotest and operating conditions.

HEA has completed numerous jobs similar to the one shown above (Similar Projects)