Methods Of Investigation And Solution Of Stress, Vibration, And Noise Problems In Pumps

Tutorialpg. 143This tutorial discusses mechanical problems that occur in pumps and their systems, and how pump users can best detect and solve these problems. The answers to pump operational or reliability problems are often not obvious, and in-depth troubleshooting must be performed to reach a successful resolution. It is shown how a concise and orderly review of all apparent problems should be developed that begins with checks of the original installation, continues through startup procedure review and data monitoring, and includes evaluation of current operational behavior. The tutorial discusses various problem types and typical causes. For example, the discussion includes overstress fractures, cyclic fatigue, rotor rubbing binding, and pump-to-driver misalignment. It also shows how these problems can have their root cause in nozzle loading, thermal distortion, resonance, recirculation during running off-BEP, and improper warmup cycles. More importantly, it covers the proven methods of analyzing and testing to determine the nature of such problems, and how to solve them. Also included are some basic mechanical concepts for inspection and assembly of pumps that can help improve reliability. A number of case histories show, by example, how best to apply these inspection, analysis, and test methods. Enough detail is given concerning the method of solution in each case that the attendees should be able to try the solution methods backs at their plants. An interesting example is also given showing how sometimes apparently unrelated failures actually have a common cause