2 times line frequency vibration on vertical pump

Vibration Diagnostic Guide - EDGE

When analyzing vibration we look at two components of the vibration signal, its amplitude and its frequency Frequency is the number of times an event occurs in a given time period the event being one vibration cycle The frequency at which the vibration occurs indicates the type of fault That is, certain types of

Vertical Pump Vibration - National Pump Company

Primary Factors Affecting VibrationVibration Limits Acceptance TestingTop of Motor Recommended Vibration LimitAlarm / Shutdown RecommendationsFactory Vibration TestingSeparation margin to structural natural frequency Operating on the structural natural frequency of the discharge head motor assembly will result in unacceptable vibration levels A field margin of Balance The higher the balance grade lower permissible unbalance the lower the vibration readings On a vertical turbine pump, the motor balance primarily drives this based on the location vibrat Alignment Misalignment will result in higher vibration levels Misalignment is typically seen between the top shaft and motor shaft Vertical Hollow Shaft VHS Motors: Purchase motor with a steady

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Pump Vibration Analysis Pumps Systems

Dec 17, 2011 · Since vibration can occur throughout a broad frequency range, Table 3 has recommended frequency ranges and lines of resolution to help find particular machine problems Severity indicates how bad the problem Table 2 is, and frequency indicates what is causing the problem Table 4

Two Times Line Frequency Peak AMP Maintenance Forums

Five pumps have been installed and tested for vibrations Three pumps tested good for vibrations Two pumps exceed specification limit One pump had highest peak at one time RPM and other pump had high peak at two times line frequency First pump showed over 100 degree phase angle difference at one time frequency

Special Vibration Considerations for Vertical Turbine Pumps

Deep Well vs Short-Set PumpsCoupling EffectVTP Aboveground StructureOther Causes of High VibrationVibration AnalysisConclusions

Despite these vulnerabilities, most deep set vertical turbine well pumps do not experience vibration problems as compared to many shorter set industrial applications as shown in Fig 1, which are more prone to these unique VTP vibration issues One of the main reasons for this difference is the high shaft axial thrust experienced by deep set pumps Unlike the typical horizontal pump, VTP impellers are not hydraulically balanced with back wearing rings or pump-out vanes This results in a high axial thrust, which is typically supported by the motor thrust bearing at the top of the pump In addition, deep set pumps require more of these unbalanced bowl stages to generate the high pressure needed to pump the water to the surface The weight of the added impellers and line shafting further increases axial thrust, which actually has a positive benefit for these flexible pumps: It provides a strong restoring moment that can suppress lateral shaft vibration forces, improve the shaft alig

Structural Vibration and Ways to Avoid It Vibration

Structural vibration is 10 times allowable vibration guidelines, even with very large deck girders supporting this skid figure 2 Example 2 : Small pump system caused resonance, vibration and continual failure of drive train components on affecting reliability on a critical process

Solving Motor Vibration Problems on Vertical Pumps ECM

Any attempt to solve vibration problems on vertical pump motors should begin with a basic frequency analysis using a portable vibration analyzer In most cases, a single vibration frequency will be dominant often at rotating speed Then, by simple process of elimination, zero-in on the source of the problem

Solve vertical pump motor vibration Processing Magazine

Any attempt to solve vibration problems on vertical pump motors should begin with a basic frequency analysis using a portable vibration analyzer In most cases, a single vibration frequency will be dominant often at rotating speed Then, by simple process of elimination, users can zero in on the source of the problem

Subsynchronous Vibration In Vertical Pumps

New Pump Mounting System Devised Initial Base Impact Test Showed Structural Natural Frequency in Excess of 5,000 CPM Initial Vibration Readings: First Installation had 0 2 IPS at 1,710 CPM Second Installation had 0 65 IPS at 1,750 CPM

Vibration Analysis Vibration Monitoring Dynapar

Consider a six-vane pump A pump with six vanes, for example, will have a vibration spike at 6X, or six times the fundamental frequency If that peak triples or quadruples, it indicates some sort of problem with the vanes Time-Waveform Analysis Time-waveform analysis can enhance machine vibration analysis

All About That Vibration: Understanding Vibration Phase

Mar 30, 2016 · The most common vibration frequency is directly caused by this spinning shaft is dubbed fundamental shaft speed or running speed and is denoted as "1X vibration " This vibration can be caused by many conditions, but among the most common is unbalance Unbalance occurs when the rotor has a heavy spot To the left is an example of an overhung rotor

Misalignment - Misalignment Vibration at 1 x rpm of Rotor

All vibration data in the diagrams are at the frequency of 1 x rpm Looking at Fig 2, the vertical amplitudes of 7 1 at the left and 2 2 at the right end may have originated from unbalance If from unbalance, the left end of the rotor will have much greater unbalance than the right end

Learn About Vibration, Volume 1: Basic Understanding of

Oct 11, 2019 · FREQUENCY = Frequency is measured in units of cpm, Hz, Orders, i e 50 cpm 750,000 cpm Knowing the frequency of vibration peaks helps to pinpoint the potential sources Frequency is used in advanced vibration analysis to identify all types of bearing fault frequencies, real time spectrums, and motor current signature analysis, etc

Mounting, Levelling and Vibration Control of: PUMPS/ COMPRESSORS

Sources of Pump Vibration If the pump and motor are well balanced and in good working order the only vibration likely to be a problem on rotary pumps is that caused by aerodynamic/hydraulic forces blade passing frequencies Nevertheless it is critical to avoid any low frequency

How to Determine Root Cause of Excessive Pump Vibration

Typical acceptable margins are 15-25 The amplitude of the vibration response can be amplified 2 5 times or higher at or near a component natural critical resonant frequency Field Vibration Problem Example The writer was recently asked to investigate an excessive vibration problem on three new replacement vertical sewage lift pumps, which

Troubleshooter's Guide to Vibration September 01, 2007

Sep 01, 2007 · Therefore all AC motors produce a 2 X line frequency vibration In power systems that operate at 60 Hz, the vibration frequency is 120 Hz In an induction motor, the poles in the stator winding produce a rotating magnetic force that acts across the air gap between stator and rotor

100 Hz vibration predominant in all 3 axes in a vertical

As the two sequences are opposing one another, this interaction leads to the two times line frequency vibration phenomenon associated with unbalanced voltage operation Section IV provides results of testing motors with various controlled levels of voltage unbalance Tables 2 through 7 provide results for individual motors

A Vibration Problem in Vertical Circulating Water Pumps

B Pump Direction Before After Change Separation In Line 1st Mode 6 75 6 13 9 19 18 27 Perpendicular 1st Mode 7 50 6 50 13 33 13 33 Natural frequency Hz Natural frequency Hz Operational vibrations were 0 12 in/s RMS or less on both pumps in both directions and were acceptable

A Brief Tutorial on Machine Vibration

Table 2 is a sample form Table 2 Vibration Survey Form Equipment Displacement Mils, peak-to-peak Filtered to 1xRPM Overall Velocity In/sec, RMS 10-1,000 Hz Overall Acceleration g/ peak 0 5,000 Hz Motor ODE Horizontal Vertical Axial DE Horizontal Vertical Axial Pump DE Horizontal Vertical Axial ODE Horizontal Vertical Axial The first


VIBRATION ANALYSIS OF VERTICAL PUMPS 63 ever, vertical pumps, such as the cooling water pumps, are generally not equipped with vibration transducers It is difficult and expensive to install underwater instrumentation to measure vibrations near the impeller Generally, the vibrations are monitored near the top of the motor, because it has been