Vibrations

1. WELCOME

2. BASICS OF VIBRATION

3. VIBRATION
CHARACTERISTICS OF VIBRATION SIGNAL
AMPLITUDE
FREQUENCY
PHASE
ORBIT

4. TYPES OF VIBRATION PICK UP
PROXIMITY PROBE
VELOCITY PICK UP
ACCELEROMETER

5. CRITERIA FOR SELECTION OF VARIOUS
TYPES OF VIBRATION PICK UP
PROXIMITY PROBE
SHAFT VIBRATION MEASUREMENT
KEY PHASER MARKER
SHAFT CENTRE LINE POSITION
BEST SUITED FOR 1 TO 500 HZ
VELOCITY PICK UP
 FOR BEARING AND STRUCTURAL VIBRATION
BEST SUITED FOR 10 TO 1000 HZ

6. CRITERIA FOR SELECTION OF VARIOUS
TYPES OF VIBRATION PICK UP
ACCELEROMETER
FOR HIGH FREQUENCY RANGE
BEST SUITED FOR 1000 HZ ONWARDS

7. UNITS OF VIBRATION
(A) DISPLACEMENT
MICRONS, PEAK TO PEAK
MICRONS, 0 TO PEAK
MICRONS, RMS
(B) VELOCITY
MM/SEC, 0 TO PEAK
MM/SEC, RMS
(C)ACCELERATION
M/SEC2, PEAK
M/SEC2, RMS
G, PEAK
G, RMS

8. Average
RMS 0 - Peak
Peak - Peak
UNITS OF VIBRATION
RMS = 0.707 x (0-Peak)
Average = 0.637 x (0-Peak)
Peak to Peak = 2 x (0-Peak)

9. SHAFT ORBIT
X
Y
Proximity
Probes

10. INSTRUMENTS FOR VIBRATION
MEASUREMENT
VIBROMETER
VIBRATION ANALYSER
FFT ANALYSER

11. TIPS FOR MAKING VIBRATION DATA MORE
USEFUL FOR ANALYSIS
LOCATION OF VIBRATION PICK UPS TO BE INDICATED
LOCATION OF PHOTOCELL TO BE INDICATED
DIRECTION OF ROTATION SHOULD BE INDICATED
KEY PHASER MARK ON ROTOR POSITION TO BE INDICATED
AXIAL VIBRATION PHASE LOGGING MUST HAVE DIRECTION
INDICATION
NAME OF VIBRATION ANLAYSER SHOULD BE INDICATED
VIBRATION UNITS TO BE INDICATED

12. TIPS FOR MAKING VIBRATION DATA MORE
USEFUL FOR ANALYSIS
WHILE GIVING CONTROL ROOM VALUES, SPECIFY THE
VIBRATION UNITS AND LOCATION OF THE PICKUPS
VIBRATION MUST BE MEASURED BY PORTABLE VIBRATION
METER NEAR CONTROL ROOM PICKUP FOR VARYING THE
CORRECTNESS OF CONTROL ROOM MEASUREMENT
PICK UP SHOULD NOT BE MOUNTED LOOSE
BRACKET FOR EXTERNAL SHAFT VIBRATION PICKUP SHOULD BE
STIFF ENOUGH NOT TO PRODUCE AMPLIFICATION / RESONANCE

13. TIPS FOR MAKING VIBRATION DATA MORE
USEFUL FOR ANALYSIS
FOR CORRECT TRENDING OF VIBRATION READINGS, SAME
LOCATION SHOULD BE USED FOR ALL PERIODIC
MEASUREMENTS

14. REASONS OF VIBRATION
IF THE MEASUREMENT IS HEALTHY, FOLLOWING MAY BE THE
REASONS OF VIBRATION PROBLEM
UNBALANCE
MISALIGNMENT
LOOSENESS
PIPE PULLS
SHAFT CATENARY / BEARING LOADING
RESONANCE
UNEQUAL FLOW PATH CLEARANCES
RUBBING

15. REASONS OF VIBRATION
SHAFT BOW
OIL / STEAM WHIRL
DEVIATED OPERATING PARAMETERS
DEFECTIVE BEARING / ASSEMBLY OF BEARING
VIBRATION TRANSMITTION FROM OTHER SOURCE
GEAR INACCURACIES
CASING DISTORSTION
CAVITATION

16. STEPS FOR RESOLVING THE VIBRATION
PROBLEM
ACCURATE MEASUREMENT OF VIBRATION DATA
COLLECTION OF OPERATING PARAMETERS
STUDY OF HISTORY OF VIBRATION BEHAVIOUR / OVERHAULING
REPORTS / RECURRING PROBLEM FACED
INTERACTION WITH O&M PERSONNELS
COLLECTION OF DETAILED VIBRATION BEHAVIOUR AT VARIOUS
CONDITIONS OF OPERATION LIKE NO LOAD RUN, RUN UP, RUN
DOWN, WITH AND WITHOUT EXCITATION, PART AND FULL LOAD
OPERATION ETC.
VIBRATION ANALYSIS TO NARROW DOWN THE REASONS OF
HIGH VIBRATION

17. STEPS FOR RESOLVING THE VIBRATION
PROBLEM
FORMULATION OF ACTION PLAN (SHORT TERM / LONG TERM)
IMPLEMENTATION OF ACTION PLAN
RESPONSE OF MACHINE AFTER IMPLEMENTATION OF ACTION
PLAN
FRESH VIBRATION ANALYSIS, IF THE PROBLEM PERSISTS
IMPLEMENTATION OF NEW ACTION PLAN
THE CYCLE OF VIBRATION ANALYSIS AND IMPLEMENTATION
OF ACTION PLAN CONTINUES TILL THE VIBRATION PROBLEM
IS SATISFACTORILY RESOLVED

18. KNOW YOUR MACHINES
KNOWLEDGE OF BEHAVIOUR FOR SIMILAR TYPE OF MACHINES
VIBRATION PRONE AREAS
INFLUENCE OF PARTICULAR OPERATING PARAMETER

19. INTERNATIONAL STANDARDS ON VIBRATION
ISO 10816 BEARING VIBRATION
ISO 7919 SHAFT VIBRATION
THERE ARE THREE LIMITS IN INTERNATIONAL STANDARDS
LIMITS FOR NEW MACHINES
ALARM LIMITS
TRIP LIMITS

20. RECOMMENDED LOCATIONS OF VIBRATION MEASUREMENTS
ON BEARINGS AS PER ISO

21. OR
Measuring
Amplifier
45O 45O
PROXIMITY
PICK-UP
L R
SHAFT
Measuring
Amplifier
VERTICAL
HORIZONTAL
L R
SHAFT
RECOMMENDED LOCATIONS OF SHAFT VIBRATION
MEASUREMENTS AS PER ISO

22. THANK YOU