Tube Pullout Testing Experience

This paper provides an overview of the use of pullout testing to determine the optimum parameters for assuring reliable tube to tubesheet joints in condensers and heat exchangers. The test is described with typical test methods, equipment and test precautions. Numerous examples of data from a variety of units, tube materials, and tubesheet materials are presented. Also included are unique tests which were performed to qualify the tube expansion procedures prior to use in nuclear facilities. These tests include mockups for pneumatic and helium leak testing, and hydrostatic testing of mockups with rolled test joints at over 600 psi. Examples will include testing with 3 roll expanders compared to 5-roll expanders in heavy gauge titanium tubes, test results with a double tubesheet arrangement, and high strength joints with thin wall titanium tubes in brass tubesheets. An example comparing the pullout forces determined with a HEI beam strip analysis to the actual pullout test data is also discussed.