NOVEL MITIGATION TECHNIQUE TO REDUCE STRESS AT PIPE WELDS CAUSED BY ACOUSTIC INDUCED VIBRATIONS (AIV)

摘要

Within blowdown and pressure relieving systems, a phenomenon known as acoustic induced vibrations (AIV) increases the risk of costly failures at branch connections, pipe supports and other discontinuities downstream of pressure relieving devices. Broadband pressure fluctuations generated during these AIV events lead to elevated stresses at welded connections. Based on recent research, modeling and measuring the effects of AIV in piping systems, it is possible to reduce the dynamic pressure fluctuations that cause AIV closer to the excitation source. This can lead to more cost effective and efficient means of reducing the likelihood of failures caused by AIV. This paper will discuss the results of full-scale testing of a novel mitigation technique that reduces pressure fluctuations that cause AIV The reduction in dynamic pressure leads to significant lowering of the overall stresses near the pipe welds at discontinuities. In addition, results indicate that a reduction in dynamic pressure can be obtained with the mitigation technique tested to a level acceptable by current screening methods.