Tube Pullout Testing

Tube pullout testing is performed to determine the amount of torque required to achieve the maximum tube-to-tubesheet joint strength in your condenser retubing project.  Pullout testing is recommended if your retubing project is utilizing a different tube material than previously installed, or if there are questions regarding the joint strength.  The pullout test is performed during the planning phases of the project. 

Overview of the Pullout Test

Tube samples of like material and dimensions will be roller expanded into mock-up tubesheets (also of like material and dimension) using the “known hole method” of tube expansion.  The rolling motor torque will vary based on specific criteria which results in varying degrees of tube wall reduction.  Each joint will then be mechanically stressed until the joint fails.  The amount of force required to break the joint will be documented.  The amount of apparent wall reduction (AWR) resulting in the strongest tube-to-tubesheet joint will be used for expanding the tubes in the condenser.