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ULTRASONIC TESTING <br />Ultrasonic testing of large diameter HDPE pipe joints is a technology that has <br />only recently been developed to the point of general acceptance in the HDPE <br />industry. Ultrasonic testing was not required in the Storke Pipeline specifications. <br />Considering the environmentally sensitive nature of the pipeline installation, Climax <br />personnel requested ultrasonic testing of the HDPE Storke Pipeline joints. A <br />company from Canada, RTD Quality Services, was contracted to perform these <br />tests. Representatives from the company's branch office in Houston, Texas visited <br />the Climax project site on October 11 and 12, 2003 and performed ultrasonic <br />testing of the HDPE fusion joints that had not yet been covered with backfill. <br />Ultrasonic testing is~accompliShed by sending sound waves through the weld <br />' area of the pipe. A device is clamped around the exterior circumference of pipe that <br />has two transducer units, one on each side of the fusion joint. A sound signal is <br />' generated in one of the transducers and' is sent through the pipe to the other unit. <br />The test unit is driven around the pipe perimeter to provide a complete test of the <br />entire pipe joint. Computer software is used to generate a graph that shows the <br />cross section of the pipe wall, including any defects. The operator then reads the <br />graph and interprets the results. This equipment was originally developed to test <br />steel pipes and tanks. It has only recently been applied to testing HDPE pipe. <br />Because of its recent development, Wheeler was not aware of its existence, or it <br />would have been recommended earlier in the construction. <br />Unfortunately, because the requirement for ultrasonic testing was not known <br />earlier, most of the new HDPE pipe had already been installed and buried. However, <br />some of the HDPE pipe was still exposed, and one 800-foot section was not yet <br />installed and was still laying on the ground surface and was available for testing. <br />All of the fusion joints that were exposed were tested by RTD, and consisted of the <br />high-pressure end of the pipeline. Every joint that was tested was found to be free <br />of flaws such as gaps, inclusions, or lack of complete welds. Refer to Appendix B <br />for complete test results. <br />5 <br />