“Good Vibrations” – MRO Magazine article from KSB Pumps
MRO Magazine recently published a good article by Mehran Masoudi from KSB Pumps on vibration in pumps and pumping systems. As we know, vibration can cause serious problems or issues for maintenance departments. This article provides some tips on things like potential sources of vibration, pump vibrations on critical speeds, piping system vibrations and diagnosing them and advice for controlling certain vibrations. Use these tips from one of the most knowledgeable engineering pump solution’s provider in the industry to stem downtime at your plant!
Below is an excerpt from the article:
Vibrations can be a serious problem in pumping systems, leading to rough, noisy operation and even damage to mechanical components. There are a variety of circumstances that can lead to strong vibrations, including balance problems and rotating components, resonance effects (when the frequency of a periodic driving force matches and natural vibration frequency of a structure) and fluid-structure interactions around a pump or in adjacent piping. The following are just some sources of vibration problems in pumps and piping systems and ways that these can be controlled.
Sources of Vibration
Well-maintained centrifugal pumps operating close to their best efficiency point (BEP) will generally run smoothly. However, rough running can occur if a pump is operated under seriously off-optimal conditions (such as with severely restricted flows). Off-optimal running can also cause extra loads on bearings and pressure pulses in the output stream. There are also potential problems associated with the intake or suction side of pumps. If the available head at the pump’s intake is less than the unit’s NPSHR (net positive suction head required), cavitation can occur, causing vibrations, unbalanced loads on rotating components and damage to the impeller and nearby surfaces. (NPSHR is determined by the pump’s manufacturer, based on test data.) Other intake problems can arise from plugged suction strainers, air entrainment and vortexing (that is, the formation of “whirlpools” near the inlets of submersible pumps when there is low water level in the sump).
You can read the whole article by downloading MRO Magazine’s November Digital Edition here. “Good Vibrations” begins on page 18, enjoy!