A nondestructive testing company uses acoustic pulse reflectometry to test tubes up to 4" ID, enabling inspection of boiler tubes as well as fin fans and other heat exchangers regardless of tube shape or material.

The Dolphin G3 system from AcousticEye, headquartered in Leusden, The Netherlands, overcomes the limitations of conventional invasive inspection techniques, the company says. With its automated analysis and report generation, there is less dependency on operator expertise.

A U.S. chemical facility relied on AcousticEye technology to inspect 2" tubes on two preheater waste-gas incinerators. The heat exchangers consisted of 454 tubes, each 2" OD x 0.109" thick wall x 35' and constructed of SA-249-TP-321L stainless steel. The heavy wall thickness and larger tube diameter were at the edge of the upper size limit of inspection capabilities for conventional techniques, according to AcousticEye. The provider performed a 100 percent baseline inspection of all tubes, using both eddy current and acoustic testing.

According to AcousticEye, all the tubes had corrosion or erosion of 10 to 100 percent through-wall depth, plus six tubes had crack-like defects at 100 percent through-wall. In addition, the acoustic technology found severed tubes that the eddy current method had incorrectly determined were just restricted or blocked.

For more information on acoustic pulse reflectometry for testing tubes, go to www.acousticeye.com.