basics of vibration
TRANSCRIPT
WELCOME
BASICS OF VIBRATION
VIBRATION
CHARACTERISTICS OF VIBRATION SIGNAL
AMPLITUDE
FREQUENCY
PHASE
ORBIT
TYPES OF VIBRATION PICK UP
PROXIMITY PROBE
VELOCITY PICK UP
ACCELEROMETER
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
CRITERIA FOR SELECTION OF VARIOUS TYPES OF VIBRATION PICK UP
ACCELEROMETER FOR HIGH FREQUENCY RANGE
BEST SUITED FOR 1000 HZ ONWARDS
UNITS OF VIBRATION
(A) DISPLACEMENTMICRONS, PEAK TO PEAKMICRONS, 0 TO PEAKMICRONS, RMS
(B) VELOCITYMM/SEC, 0 TO PEAKMM/SEC, RMS
(C)ACCELERATIONM/SEC2, PEAKM/SEC2, RMSG, PEAKG, RMS
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)
SHAFT ORBIT
X
Y
Proximity Probes
INSTRUMENTS FOR VIBRATION MEASUREMENT
VIBROMETER
VIBRATION ANALYSER
FFT ANALYSER
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
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
TIPS FOR MAKING VIBRATION DATA MORE USEFUL FOR ANALYSIS
FOR CORRECT TRENDING OF VIBRATION READINGS, SAME
LOCATION SHOULD BE USED FOR ALL PERIODIC
MEASUREMENTS
REASONS OF VIBRATION IF THE MEASUREMENT IS HEALTHY, FOLLOWING MAY BE THE
REASONS OF VIBRATION PROBLEMUNBALANCE
MISALIGNMENT
LOOSENESS
PIPE PULLS
SHAFT CATENARY / BEARING LOADING
RESONANCE
UNEQUAL FLOW PATH CLEARANCES
RUBBING
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
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
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
KNOW YOUR MACHINES
KNOWLEDGE OF BEHAVIOUR FOR SIMILAR TYPE OF MACHINES
VIBRATION PRONE AREAS
INFLUENCE OF PARTICULAR OPERATING PARAMETER
INTERNATIONAL STANDARDS ON VIBRATION
ISO 10816 BEARING VIBRATION
ISO 7919 SHAFT VIBRATION
THERE ARE THREE LIMITS IN INTERNATIONAL STANDARDSLIMITS FOR NEW MACHINES
ALARM LIMITS
TRIP LIMITS
RECOMMENDED LOCATIONS OF VIBRATION MEASUREMENTS
ON BEARINGS AS PER ISO
OR
Measuring
Amplifier
45O 45O
PROXIMITY PICK-UP
L RSHAFT
Measuring
Amplifier
VERTICAL
HORIZONTALL R
SHAFT
RECOMMENDED LOCATIONS OF SHAFT VIBRATION
MEASUREMENTS AS PER ISO
THANK YOU