PDM IMPLIMENTATION

Implementation of Condition Monitoring

By : Uttam Kumar Misra (MIE)(Condition Monitoring )

What is CBM?

• CBM is a philosophy of managing changes in Maintenance strategy.

“The ultimate objective of a CBM program is to ensure the availability of the machine for safe and reliable operation during its useful life at optimum maintenance cost”

Why CBM is required

• Quality CBM improves the QUALITATIVE

availability of equipment due to enhanced monitoring of the same.

OrCBM ensures the Reliable performance of the

equipment due to enhanced monitoring of the same.

Why CBM is required (contd…)

• Cost BenefitsExtended PM frequencies, lesser job-contracts.Minimum equipment damage/repairs.Reduced over time.Minimum oil use and disposal.Less inventory through reliability enhancement.Indirect cost-Less part loading due to equipment outage

Why CBM is required (contd…)

• Time Factor Reduced down time of equipment through

scheduled Vs unscheduled repairs.High Mean-time-difference between outages.

An approach to Best Condition Monitoring Practices

Factors affecting Industrial applicationsWhere downtime cost is predominantly highWhere a safety risk is particularly likely to arise from

the breakdown of the machinery.Where accurate and advanced planning of

maintenance is essential.Where plant/equipment is of recent design & may

have residual development problems

Where operators cannot be expected to detect faults in expensive equipment whose breakdown may result in serious damage.

Where instruments or other equipment required for condition monitoring can be used or is already being used.

Where the manufacturer can offer a condition monitoring service to users of its equipment.

Pertinent IndexesPotential gross savings by applying condition

monitoring to the industry would be about Some% of the added value output.

Average annual maintenance expenditure on plant & machinery to Average annual capital invested in plant & machinery is about 80%.

Overall Equipment Effectiveness (%) =Availability X Machine Efficiency X Quality Output

(>95%)

Percentage forced outages unit wise – Cost wise & Total downtime wise

Plant load factorSupply frequencyComparison of pertinent failures – Frequency

wise (repetitive type & non-repetitive type) and Total downtime wise (repetitive type & non-repetitive type).

Availability-1%Higher availability performance (95% – 99%) for an investment of xx USD in a plant would accrue savings of yy USD

Technologies being used for CBM:1. Vibration Analysis 2. Ultrasonic and Acoustic Emission3. Thermography4. Dissolved Gas Analysis5. Oil Analysis6. Noise And Acoustics

Technologies being used:

7. Wear Debris Analysis8. Corrosion9. Shock Pulse10. Appearance And Odor11. Level Leakage And Flow12. Power Performance And Efficiency

Technologies being used:13. Steady State(Speed , Temperature etc) 14. Electric Motor (Air gap, Power ckt fault)

Machines Covered Under Vibration Technology:

Equipment FrequencyBlower, Wter Pump,……………………..etc

Every Month

Vibration technology successful implementation steps

• Plant :• Area: • Floor plans and maps:• Total machine :• Machine identification:• Machine diagram: • Machine information data sheet :• Types of Machine:• Criticality of each piece of machine:• Measurement point:• Contract information for resources:

• Transport:• Vibration instrument:• Supporting instrument :• Hardware and Software:• Man power:• Safety:• Frequency of measurement:• Total workload and scheduling:• Establish CBM/PM work order for collecting all possible

information regarding machine:• CBM Checklist:• Different level of meeting:• Reporting:• Detailed analysis report:

• Daily report:• Weekly report:• Monthly report:• Critical/unsatisfactory equipment reporting:• Stabilizations of system:• Establish maintenance manpower training• Documentation• KPI

• Book-keeping-Whether a program is performed in house or contracted out, it is essential that adequate prepared and maintained it is recommended that a notebook is prepared which includes, limited to section concerning.

• Floor plans and maps- It is critical that personnel are able to find and identify the equipment monitored. These are also invaluable in establishing the routes .and it will be helpful when new personnel join the program.

• Machine diagram- A picture is worth a thousand words • Machine information data sheets- When analyzing the data it is very helpful to have

as information about the machine at hand as a possible. • A schedule for obtaining route data- Making the task more manageable and setting

of goals • Contact information for resource's- that have provided or can provide pertinent

information,manufacturer,part supplier,operators,supervisors name and extensions. • Outlines of procedures-this include everything from how to collect data to the

parameter being used in the spectrum analyzer, to method and guide and report on the data. As these items may change from time to time and from machine to be documented.

• Summary of case history -When a problem is identified the report should be cataloged it may be benefited from again at a later date .

• Cost analysis information - What would have happened had the problem not been identified earlier using vibration analysis.

• AMS suite for vibration technology includes• Data base creation • Route creation• Data collection• Data communication• Analysis • Reporting

• Analysis parameter Set• F max: • Waveform length: • Resolution-:• Averaging mode-:• Filtering-:• Alarm limit set: • Machine vibration Severities:• Sampling rate:• Bandwidth:• Overlap:• Fault frequency set:

SOUND LEVEL MEASUREMENT• Measurement every six month, is as per the safety

requirement.• Turbine floor, Compressor house, pump house, • etc

THERMOGRAPHY:

Sl. No. Area Description Frequency

1. Furnace wall Quarterly

2 etc

3.

4.

DISSOLVED GAS ANALYSIS• Oil samples from transformers are being regularly

sent to Analyse • Whenever the level of dissolved gases is more than

the norms the frequency of DGA is increased.

OIL ANALYSIS• Being done regular interval• Primarily the analysis includes moisture content,

viscosity, Total acid number, Mechanical impurities, PQ index etc.

• On observation of any abnormalities detailed analysis of sample will be done by WEAR DEBRIS ANLYSER.

OIL ANALYSIS:

Sl.No. Equipment Frequency

1. Hydraulic oil Half yearly2. etc

3.

4.

5.

6.

Selecting level of CM activity – Practices

The complete Plant – Plants of high product demand or major strategic significance.

Key Machines Only – Applicable to large industries. A few critical components of key machines – Widely

applicable to industry.(A few critical components are selected based on the past failure experience & monitored for known failure modes using appropriate techniques.

Selecting Machines for Monitoring

Selecting machines on the basis of Loss of productive earning capacityFailure damage potentialSafety

Selecting Components for Monitoring

Selecting components on basis of Criticality in terms of machine reliabilityHigh performance dutyLong replacement / delivery timeHave lower life than the rest of the machine

Component to be Monitored

Possible general monitoring method

Visual Behaviour

Vibration

Wear Debris

Stationary components:CastingsMountings & foundationsTanks & containersPressure vesselsPipesHeat exchangersScreens and separatorsStator Blades

SELECTING METHODS OF MONITORING

Rotating components

ShaftsMachine rotorsTurbine bladesImpellors and propellersWheelsGearsChain drivesFlexible couplingsPulleys and beltsGovernors

Reciprocating components

PistonsLinkages & leversCams & tappetsValvesCables & chainsBellowsDiaphragmsSpringsGuides & SlidesSplines

Friction components BreaksClutchesVibration dampers

Bearings PlainRollingFlexure

Seals LipMechanicalPacked glandsWindbackLabyrinthPiston rings

Wear resistant surfaces HardElastic

Manufacturing tools 

Cutting toolsMetal working toolsCasting and moulding dies

Working fluids HydraulicCooling and heat transferLubricants  

MACHINE PERFORMANCE MONITORING Monitoring method of m/c performance

Typical example Remarks

Measuring the quantity of the output or variations in the quantity

Measuring the delivery from a conveyor or pumping system

Measurement of the mean output rate at standard conditions can indicate the existence of a problem. If the delivery fluctuates, the condition under which it does this, may indicate the nature of the problem.

Measuring the quality of the output of variations in the quality.

Noting accuracy within tolerance of the output of machine tools. Observing pattern variations in the fabric produced by textile machines. Observing size distribution in the output from a crushing mill.

This can provide a very convenient monitoring method for direct use by machine operators.It will indicate the existence of a problem and with experience of its interpretation, can indicate the nature of the problem as well.

Monitoring method of m/c performance

Typical example Remarks

Measuring the relationship between the input and output of the machine.

Comparing the fuel consumption and electrical output of a diesel generator.Measuring the distance traveled per unit of fuel consumption of a transport vehicle.

Can indicate the existence of problem using measurements, which are often already recorded for other reasons.

Simultaneous measurement of two output variables, and a comparison between them, on an allowable operating envelope

The flow/pressure rise relationship for a pump. The temperature difference/flow relationship for a heat exchanger.The pressure drop/flow relationship for a separator.

This method of monitoring enables the condition of the machine or plant item to be determined, independently of any other changes, which may have occurred in the system of which it is a part.

COMPONENT BEHAVIOUR MONITORING 

Component Function (s) Method of monitoring component behaviour

Seals (static and dynamic)

To prevent leakage Detection of leakage by: Smell, Visual inspection, Snifting, Noise

Structural components (casings, containment vessels, load carrying machine parts).

To remain intact without progression of cracks etc.

Strain gauging.Brittle lacquersAcoustic emission (listening to the sound generated by the strain of materials using a microphonic transducer attached to the surface). Crack detection by magnetic eddy current, and liquid penetrant methods.

Bearings To located shafts as required, but with the minimum of resistance to rotation

The measurement of shaft location by proximity transducers. The measurement of bearing temperature as a check on frictional heat generated by malfunctions.

Friction components (brakes, clutches).

To provide controlled and relatively high friction with the minimum of wear and overheating

Periodical wear measurement. Temperature measurement to detect general overheating.

Cylinder liners To guide pistons and provide gas seals with the piston rings with a minimum of wear.

Wear detection with wear sensors. Temperature measurement. Blow by detection by ultrasonic sound emission.

Condition Based Maintenance – Implementational Steps

Step –1Establish an inventory of all physical assetsDevelop an equipment identification (codification) plan

down to the component level. Develop an equipment data card ( Location, Make, Model,

Manufacturer, Supplier, Major specs, Drawing Nos. Foundation details, Major sub assemblies, Bearing details etc.)

Organise all technical information

Step – 2Develop a process flow chart indicating all equipments

down the line. Establish criticality of each piece of equipment (Major

factors to be considered are – Impact on Production, Safety, Cost of equipment Maintenance requirements-resources, RAM, & Effect on Quality)

Step – 3Compile Condition Based Maintenance data for all the

critical equipments (in the first phase) – Techniques applicable, Measurement parameters applicable standards, Alarm & Critical Levels

Measurement points, frequency etc.Develop CBM checklistsStep – 4Establish total workload (manhours)Schedule CBM activities evenly throughout the yearStep – 5 Incorporate Total Productive Maintenance concepts

(autonomous maintenance, small group activities, one point lessons, action on major losses, and 5S) to improve maintenance function.

Step – 6Establish PM/CBM work order (basic document for

collecting all possible information on maintenance activities and resources.

Collate for data entryStep – 7Computerisation of Maintenance function including

its interfacing with spares management and costing deptt. Computerisation to generate m/c history and various reoports.

Step – 8Design reporting parameters, indexes, different

levels of reports.Carry out detailed analysis - RAM, B/d Analysis,

Maintenance Costing, Performance analysis etc.Feedback to respective groupsStep – 9Stabilisation of the systemEstablish Maintenance manpowerTraining

THANKS